Causes of delays in construction industry and comparative delay analysis techniques with SCL protocol

Parvaneh Shahsavand (School of Architecture, University of Tehran, Tehran, Iran) (Young Researcher Club, Azad University, Varamin, Iran)
Akbar Marefat (School of Architecture, University of Tehran, Tehran, Iran)
Majid Parchamijalal (Department of Project and Construction Management, University of Tehran, Tehran, Iran)

Engineering, Construction and Architectural Management

ISSN: 0969-9988

Publication date: 21 May 2018

Abstract

Purpose

The purpose of this paper is to reveal the main causes of delays in the projects are from the client (relative importance index (RII)=0.716), labor and equipment (RII=0.701) and contractor (RII=0.698). Hence determining the contractual responsibility of delay is the most likely source of dispute in construction projects and many techniques have been used in the courts to demonstrate the criticalities of a delay event on the project schedule. Therefore, authors try to investigate all process-based techniques of delay claims and evaluated and conformed them with principles by Society of Construction Law (SCL) protocol and Association for the Advancement of Cost Engineering International (AACEI) in order to choose the best techniques based on the specific circumstances of each project.

Design/methodology/approach

This section is divided into two distinct parts: refers to the methods used to assess the perceptions of clients, consultants, and contractors on the relative importance of causes of delay in construction industry; and refers to advantages and disadvantages of various techniques used to analyze delays and their conform with SCL protocol. A questionnaire was developed to assess the perceptions of clients, consultants, and contractors on the relative importance of causes of delay in Iranian construction industry. The respondents were asked to indicate their response category on 78 well-recognized construction delay factors identified by authors.

Findings

In total, 78 causes of delay were identified through research. The identified causes are combined into seven groups. The field survey included 58 contractors, 55 consultants, and 62 client. Data collected were analyzed by RII and Statistical Package for Social Sciences (SPSS). The authors identified main causes of delay and ten most important causes, according to Table AII, from the perspective of three major groups of participants (clients, consultants and contractors). The ranking of categories of causes of delay, according to Table I, were: client-related causes (RII=0.716); labor and equipment category causes (RII=0.701); contractor-related causes (RII=0.698); material-related causes (RII=0.690); design-related causes (RII=0.666); external causes (RII=0.662); and consultant-related causes (RII=0.662). But according to the discussions and given that determining the contractual responsibility of delay is the most likely source of dispute in construction industry and many techniques have been used in the courts to demonstrate the criticalities of a delay event on the project schedule.

Originality/value

All process-based techniques of delay analysis have been present in this paper and categorized in 11 groups. In order to understand the advantages and disadvantages of them by clients, contractor and consultant, a thorough review conducted to reveal the nature of techniques. In the next step, given that selecting the most appropriate technique based on constraints and specific conditions of each project is one of the most important steps to carry out a successful delay analysis. The authors conformed, all process-based techniques of delay analysis, by SCL protocol and AACEI principles. Finally, the result of this match was brought in order to choose the best technique based on the specific circumstances of each project.

Keywords

Citation

Shahsavand, P., Marefat, A. and Parchamijalal, M. (2018), "Causes of delays in construction industry and comparative delay analysis techniques with SCL protocol", Engineering, Construction and Architectural Management, Vol. 25 No. 4, pp. 497-533. https://doi.org/10.1108/ECAM-10-2016-0220

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Publisher

:

Emerald Publishing Limited

Copyright © 2018, Parvaneh Shahsavand, Akbar Marefat and Majid Parchamijalal

License

Published by Emerald Publishing Limited. This article is published under the Creative Commons Attribution (CC BY 4.0) licence. Anyone may reproduce, distribute, translate and create derivative works of this article (for both commercial & non-commercial purposes), subject to full attribution to the original publication and authors. The full terms of this licence may be seen at http://creativecommons.org/licences/by/4.0/legalcode


Introduction

In construction, delay could be defined as the time overrun either beyond completion date specified in a contract or beyond the date that the parties agreed upon for delivery of a project. To the owner, delay means loss of revenue through lack of production facilities and rentable space or a dependence on present facilities. In some cases, to the contractor, delay means higher overhead costs because of longer work period, higher material costs through inflation, and due to labor cost increases.

Therefore, completing projects on time is an indicator of efficiency, but the construction process is subject to many variables and unpredictable factors, which result from many sources and it is necessary that a detailed assessment be conducted and calculates the loss resulted from delays on both parties in the projects with time required for the extension of projects time if the project is delayed.

A lot of research efforts have been made to study delay causes in different countries. For example, Odeh and Battaineh (2002), Vilventhan and Kalidindi (2016) showed that owner interference, inadequate contractor experience, financing and payments, labor productivity, slow decision making, improper planning, and sub-contractors are among ten top most important factors causing delay in Jordan; Maura et al. (2007) discovered that design errors, client liability, project specification and direct change order by the client are the major factors that cause the time and cost overrun in Portuguese; Abdul-Rahman et al. (2006) conducted a study on delay mitigation in the Malaysian construction industry; they proved that a financial problem is confirmed by the survey as the main causes of delay.

Hence, one of the most important problems in the construction industry is delay and it is essential to define the actual causes of delay in any construction project. So choosing an appropriate delay analysis method is an important part of construction industry. The famous process-based methods include the global impact, net impact, adjusted as-built CPM, as-planned expanded, but-for, snapshot, time impact, windows and isolated delay type techniques (Yang et al., 2006; Yang and Kao, 2007). These techniques are applied to prepare the logical basis to persuade their claims concerning the extension of time and financial burden but each delay analysis method adopts a different approach to identify delay impacts and may yield different results.

But in Iran, there is not a comprehensive and practical package for delays analysis techniques to determine which one is appropriate in accordance with the feature of the project. So the authors examine all delay analysis techniques that are frequently used in the construction project in Iran in order to determine which delay analysis techniques is appropriate for each construction project.

In this paper the main causes of delays in Iranian construction projects have been determined and the aim of this study is to operate a method based on which one could select the delay analysis techniques appropriate to the nature of the projects that what is needed to implement this method is to analyze the Society of Construction Law (SCL) protocols and analytical delay techniques and then to implement standards of protocol with delay analysis techniques.

Literature review

Many researchers have studied the causes of delay and delay analysis techniques in the construction industry. We have broken the studies into two parts: studies on causes of delay; and studies on delay analysis techniques.

Studies on causes of delay

Delay in construction is a global phenomenon affecting not only the construction industry but the overall economy of countries as well (Sambasvian and Soon, 2007; Parchamijalal and Shahsavand, 2016). Delays in construction are caused by several factors. Ahmed et al. (2003) grouped delays into two categories – internal causes and external causes. Internal causes arise from the parties to the contract (e.g. contractor, client, and consultant). External causes, on the other hand, arise from events beyond the control of the parties. These include the act of God, government action, and material suppliers. Sweis et al. (2008) studied the causes of delay in residential projects in Jordan and concluded that financial difficulties faced by the contractor and too many change orders by the owner are the leading causes of construction delay. Abd El-Razek et al. (2008) in a similar study in Egypt found that the most important causes of delay are financed by contractor during construction, delays in contractor’s payment by owner, design changes by owner or his agent during construction, partial payments during construction, and non-utilization of professional construction/contractual management. Sambasvian and Soon (2007) identified the delay factors and their impact on project completion in the Malaysian construction industry. The results indicated that the ten from a list of 28 different causes of delay were: contractor’s improper planning; contractor’s poor site management; inadequate contractor experience; client’s inadequate financial resources and payments for completed work; problems with subcontractors; shortage in material; labor supply; equipment availability and failure; lack of communication between parties; and mistakes during the construction stage. Assaf and Al Hejji (2006) conducted a survey on time performance of large construction projects in Saudi Arabia. The survey had 73 different causes of delay. He studied the importance of various causes from the viewpoint of contractors, consultants, and owners. The most common cause of delay identified by all the parties was “change order.” He also found that about 70 percent of the projects experienced time overruns.

The previously mentioned studies were generally focused on finding causes of delays. Some of these studies identified very limited (lacking) factors or ignored some important groups. This may be misleading or may result in wrong analysis. In this paper, through a comprehensive literature review and interviews with highly experienced construction professionals, the authors attempted to use the relative importance index (RII) method in the quantification of the relative importance of a comprehensive list of delay factors in construction projects in Iran.

Studies on delay analysis techniques

Project managers and schedule (timing) analysts do often face with the problem of how to analyze the complicated delays and resolve the claims resulted from it. In addition, in most of the contracts of construction, it is not specified which method would be used to evaluate and analyze delays. On the other hand, the contractor and client have different views against analysis and determination of responsibility for delay. As a result, calculating delays and determination of responsibilities of each of the party is an important issue. Therefore, project managers must have a systematic approach for analyzing delays and allocation of responsibilities. Since there are different methods to analyze delays such as: pervasive influence technique, Bar chart or Gant chart technique, collapse technique or (but because), critical path method, time impact technique, global impact technique, net impact technique, impacted as-planned technique, collapsed as-built technique, sectional technique or snapshot technique, isolated delay type technique. So choosing an appropriate delay analysis technique for calculation of the effects of delay on project is a critical decision that is discussed in this paper (Hoshino and Livengood, 2011).

SCL has identified some factors that should be considered in choosing the method of delay analysis that includes the conditions related to the contracts, nature of causal events, value of claims, time in hand, recorded information, information of the existing time plan and planner’s experience on the project (Braimah, 2013; Yangand Kao, 2012). SCL protocol is intended to act as an aid to the interpretation of the delay and disruption provisions contained in standard of civil engineering and building contracts and to act as a guide to the manner in which the managers ought to properly prepare delay and disruption claims and how adjudicators, arbitrators and judges ought to properly determine them. The protocol does not fully reflect the provisions concerning delay and disruption contained in certain standard forms and is not intended to have contractual status, it is believed that it is at least a useful guidance document.

Arditi and Pattanakitchamroon (2006) discussed selecting a suitable delay analysis method and concluded that the most appropriate analysis method depends on information available, time of analysis and capabilities of the method, as well as time, funds and effort allocated to the analysis. Bubshait and Cunningham (1998) proposed an approach for selecting one suitable method among the as-planned method, the as-built method, and the modified as-built method. Their approach consists of four scenarios, each comprising various approved schedules (network or bar chart) with different evidence and progress reports. They concluded that method selection depends on the time and resources available, and on the accessibility of project control documentation. Mohan and Al-Gahtani (2006) discussed ten delay analysis techniques in analysis flow and compared them in resolving the issues of real time delay, concurrent delay and pacing delay. Based on study results, Mohan and Al-Gahtani proposed a desirable delay analysis system consisting of 11 requirements, such as the requirement for the project schedule to be updated every day, taking account of all delays and changes in total floats.

Methodology

This section is divided into two distinct parts: refers to the methods used to assess the perceptions of clients, consultants, and contractors on the relative importance of causes of delay in construction industry; and refers to the nature of process-based techniques used to analyze delays and their conformity with SCL protocol.

Experts’ perception of causes of delay

A questionnaire was developed to assess the perceptions of those in the Iranian construction industry on the relative importance of causes of delays. Then the questionnaire was filled out by highly experienced construction professionals including project managers, site managers, technical office managers, technical office engineers, procurement managers, and technical consultants. The collected data were analyzed through the RII method. RII or weight is a type of relative importance analyses. RII was used for the analysis because it best fits the purpose of this study. The analysis included ranking the different causes according to the relative importance indices. The analysis revealed the factors and groups that contribute most to delays.

The respondents were asked to indicate their response category on 78 well-recognized Construction delay factors identified by authors. These causes were categorized into the following seven major groups. Client-related causes (with 19 factors); contractor-related causes (with 13 factors); consultant-related causes (with 9 factors); design-related causes (with 8 factors); material-related causes (with 8 factors); labor and equipment category causes (with 8 factors); and external causes (with 13 factors). A five-point Likert scale ranging from 1 (very low) to 5 (very high) was adopted to capture the importance of causes of delays. Before distributing the questionnaires, a small interview with industry professionals was conducted that includes a 15 clients, 15 consultants and 15contractors. The basic purpose of this interview was to verify the completeness of the questionnaire in capturing the factors relevant for Iran. All the respondents agreed that the questionnaire was sufficient to capture the causes of delays. We distributed the questionnaires through our co-workers in Public Works Department of Iran, developers, consultants and construction firms. Our co-workers in turn distributed to their friends. This sampling method enabled us to obtain a large number of completed questionnaires quickly and economically. In total, 250 sets of questionnaires were distributed to the potential respondents at all levels in the organizations within the construction industry. In all, 100 sets were distributed to clients, 70 sets to consultants and 80 sets to the contractors. Of the 250 questionnaires, 175 sets (70 percent) were returned and there were 62 sets (62 percent) from clients, 55 sets (79 percent) from consultants and 58 sets (73 percent) from contractors.

The nature of process-based techniques

All process-based techniques of delay analysis have been present in this paper and categorized in 11 groups. In order to understand the pros and cons of them, a thorough review conducted with the participation of clients, contractor and consultant to reveal the nature of these techniques. The results of this review on techniques have been obtained based on several years’ experiences of the client, consultant and contractor and studies that have been done by authors .In the next step, the most appropriate technique has been selected based on constraints and specific conditions of each project, which is one of the most important steps to carry out a successful delay analysis. The authors conformed, all process-based techniques of delay analysis, by SCL protocol and Association for the Advancement of Cost Engineering International (AACEI) principles. The SCL protocol recommends that wherever possible, an appropriate method should be agreed and adopted by the parties before retrospective delay analysis is carried out. The protocol gives guidance on the appropriateness, or otherwise of different types of retrospective delay analysis to different evidential situations. The protocol suggests that if the method is not agreed between the parties, then this failure to agreement should be taken into consideration by the arbitrator, or judge when awarding the costs of the dispute. Finally, the result of this match was brought in order to choose the best technique based on the specific circumstances of each project.

Data analysis

Kometa et al. (1994) and Sambasvian and Soon (2007) used the RII method to determine the relative importance of the various causes of delays. The same method was adopted in this study. RIIs are calculated for each factor as in the following equation:

(1) ( RII ) = w A N = 5 n5 + 4 n4 + 3 n3 + 2 n2 + 1 n1 5 N
where RII is the relative importance index; W the weighing given to each factor by respondents (ranging from 1 to 5); A the highest weight (i.e. 5 in this case); and N the total number of respondents. The RII value had a range of 0 to 1 (0 not inclusive); the higher the RII, the more important was the cause of delays. The causes were ranked based on RII values. From the ranking assigned to each cause of delays, we were able to identify the most important factors or causes of delays in Iranian construction industry. For more information about the list of causes of delays categorized into seven groups refer to Table AI.

In Table AII, the main causes of delays in each category specified and have been ranked based on RII. For more information on the way of ranking and 78 causes of delays from experts’ views refer to Table AII (Table I).

Table II, summarizes RII and ranking of the categories of causes of delay as perceived by all respondents.

Analysis of variance (ANOVA)

ANOVA is used to get the average scores obtained by construction industry experts given to each of the causes of delay (i.e. RII) and every seven fold causes has been rated using these scores and the rate of their being under the effect on the projects has been prioritized.

According to Levene’s test, the significance of this test is more than 0.05 and parametric tests such as ANOVA can be used. ANOVA is a collection of statistical models used to analyze the differences among group means. In the ANOVA setting, the observed variance in a particular variable is partitioned into components attributable to different sources of variation. Factorial ANOVA can be balanced or unbalanced (Gelman, 2005; Armstrong et al., 2002). This is to say, you can have the same number of subjects in each group (balanced) or not (unbalanced). The results shown in Table III indicate that the data were balance and there is no significant difference among respondents’ data, at the community.

Pearson’s correlation

Data normality test (one sample K-S test) clarifies that the calculated p-value is greater than the significant level which is equal to 0.05 (p-value > 0.05). This in turn denotes that data follows normal distribution and we can use Pearson’s correlation test.

In order to test the degree of agreement between the three groups of respondents, a correlation analysis was done using Pearson’s correlation coefficient. Table IV gives the results of this analysis. Based on this test, view point of clients and contractors are not the same as consultants and have different opinions from each other. On the other hand, view point of Clients and the contractor were nearly identical to rank of delay factors.

So based on the perceptions of clients, consultants, and contractors on the relative importance of causes of delay in Iranian construction industry and data analysis using Statistical Package for Social Sciences (SPSS), we found that clients (with 19 subcategories and RII=0.716); labor and equipment (with 8 subcategories and RII=0.701) and contractors (with 13 subcategories and RII=0.698), respectively, have the highest impact in construction industry.

In this paper, at first all the delays have been identified and ranked and validated from client, contractors and consultants, viewpoint three factors of ten causes that lead to delays and are of main causes have been identified in Table AI. Then, in Table II, based on the opinions of clients, contractors, consultants and all the three, the index of relative importance and ranking have been ranked in seven categories in which delays had been examined. In the following, in order to lower or remove those after interviewing with experts, 40 alternative have been extracted and presented in Table AIII that performing this task could prevent delays emergence in next projects.

Given that delays are an integral part of construction industry. Therefore, the authors in second part of this paper discussed the pros and cons of all process-based techniques of delay claims and compared the versatility of each of them with SCL protocol.

In Table V, all the strengths and weaknesses of delay analysis techniques are studied in detail, and it should be noted that none of these methods are not preferred over one another and according to the conditions of project and available documentation; one of this methods can be used in the project. Therefore, among them and with regard to the specific and better features that some of these techniques have than others, in terms of complexity, they can be separated into two levels, namely:

  1. The first level that is shown in Table V (Items 4, 6 and 7), represents a simple method that a major problem in view of the simplification in these techniques is that they do not have a mechanism for exact determination of the types of delays, as a result, those delays that should not be applied in the analysis, are considered and therefore unrealistic and exaggerated results are obtained. In addition, these techniques consider the timing schedule only once (primary schedule) and assume that the critical path is fixed for the entire project. This makes the delays in contrast to what has really happened, potentially be considered as critical and also global impact technique, against two other techniques, has another weakness that has not the ability to consider the delays at the same time.

  2. The second level shows the detailed procedure, which includes the techniques that have been identified with number 2, 5, 8, 9, 10 and 11, in Table V. These techniques offer convenient and reliable methods for analyzing delays. At the same time enhancing and mitigation methods with analysis, define the type of delay. Increasing and decreasing methods while doing the analysis, identify the type of delay, too. Of course, the main problem is that these two techniques are applied only once to the scheduled timing and thus no change in the critical paths during the project implementation is accepted and also, simultaneous delays are not considered, of all the methods, both time impact technique and snapshot technique, because of considering the impact of delays during project and CPM scheduling, are known as systematic and reliable methods for quantifying delays in construction projects. The biggest problem with these techniques is that during the analysis none of them identify the delay type accurately and a series of other analyses to determine the contribution of the employer and the contractor of the delay is necessary. Another disadvantage of time impact technique is that the delay activities has been analyzed and examined separately and the impact of simultaneous delays is not specified during the analysis and due to a number of delayed events in the project, the analysis may be very time consuming. Accuracy of both time impact technique and snapshot technique is a function of the number of intervals between analyses that occur during the project from beginning to end. Isolated delay type technique relying on the strengths of previous techniques, provide a practical method for analyzing delays. The mentioned technique showed that in the case of reliable information and reports available in the project, it is superior to the other techniques. Isolated delay type techniques study the delays during the analysis process and therefore it reduces time needed for delay analysis and so the expense is decreased. This technique considers the simultaneous delays in various activities.

The SCL protocol has been prepared by the SCL for determining extensions of time and compensation for delay and disruption. It exists to provide guidance to all parties in the construction process when dealing with delay and disruption matters. It recognizes that transparency of information and methodology is central to both dispute prevention and dispute resolution.

The object of the protocol is to provide useful guidance on some of the common delays and disruption issues that arise in construction projects. The purpose of the protocol is to provide a means by which the parties can resolve these matters and avoid unnecessary disputes. A focus of the protocol therefore is the provision of practical and principled guidance on proportionate measures for dealing with delay and disruption issues that can be applied in relation to all projects, regardless of complexity or scale, to avoid disputes and where disputes are unavoidable to limit the costs of those disputes. Users of the protocol should apply its recommendations with common sense. The protocol is intended to be a balanced document reflecting equally the interests of all parties to the construction process.

Given that the delays occur in every construction project and the significance of these delays varies considerably from project to project, hence identifying the type of delay analysis techniques and selecting the most appropriate technique based on constraints and specific conditions of each project is one of the most important steps to carry out a successful delay analysis. But unfortunately in Iran, because of the lack of accurate knowledge on a variety of techniques all parties cannot use the most suitable delay analysis techniques for each project and this leads to create a lot of disputes and claims in projects. Hence the delay analysis techniques for further investigation are evaluated and conformed with principles which have been released in Table VI by SCL and (AACEI. Finally, the result of this match, the rate of using each of these techniques in various stages of construction projects, the plausibility of each of these techniques in court, the level of expertise needed to experts analyst delays and the amount of time required for the analysis depends, the use of each of these techniques in large and complex projects, that regarding the mentioned items, each technique could be selected with respect to the kind of project regarding the feature it has. The information needed to be analyzed the delay, etc. have been shown in Table VI.

By examinations carried out and interviews with the experts, the Iranian project have been divided into three groups from magnitude perspective and into 6 categories from delay rates perspective that regarding their features and the results obtained from complete comparison of the methods of delays analysis (Tables V and VII) a proper method to examine delay in six above classes are suggested as the following table.

Conclusion

  1. Construction projects often suffer from delays due to a wide variety of reasons, which can have severe financial impact on the project. As a result, delay claims may be filed. But delays can be avoided or minimized when their causes are clearly identified. However, in case of delays the analysis of its impact, the causes, and effects of the delaying activities is one of the most complicated types of claims analysis. The aim of this paper is to identify the delay factors in construction projects and introduction type of delay analysis techniques for applying more reliable and precise techniques in order to reduce the frequency and to mitigate the severity of disputes and litigation due to delay claims because delays are considered to be a serious problem in the construction industry.

    Hence through a detailed literature review and interviews with experts from the Iranian construction industry, a total of 78 different delay factors were identified and categorized into seven groups the field survey included 58 contractors, 55 consultants and 62 clients. Data collected were analyzed by RII and SPSS. We identified main causes of delay and ten most important causes, according to Table AI.

  2. According to the discussions and given that determining the contractual responsibility of delay is the most likely source of dispute in construction industry and many techniques have been used in the courts to demonstrate the criticalities of a delay event on the project schedule, the authors discussed the pros and cons of all process-based techniques of delay claims and compared the versatility of each of them with SCL protocol in order to choose the best techniques based on the specific circumstances of each project.

  3. The Iranian projects have been classified from magnitude perspective into three categories and from the perspective of emergence of delays; they have divided into six groups. Several methods of analyzing delays have been compared from different dimension (Tables V-VII). So regarding the features of projects one could select the most suitable methods kind based on Table VIII. For example, for those mega projects with many delays, i.e. 6th class, the methods of analysis of delays has been selected as the most suitable method.

In this paper, by providing all the causes of delays in Iranian construction projects, all parties can be familiar with the variety of delays and implementation of solutions which are presented in Table AIII in appendixes, they can decrease the causes of delays in projects. But delay cannot be controlled from time to time and occurs in every construction project and the significance of this delay varies considerably from project to project. Unfortunately in Iran, there is not a comprehensive and practical package for delays analysis techniques to determine which technique is appropriate for each project. So the implications of this paper could be used as a complete package, in order to select the appropriate delays analysis techniques according to the circumstances of each project. Hence, by the use of SCL protocol guidance and according to the circumstances of each project the authors show on which basis choose the best delay analysis technique to reduce the confusion and disputes arising from the delays in construction projects.

Importance of delay causes

No. Client RII Contractor RII Consultant RII Overall RII
 1 Delays in sub-contractors work 0.77 Inadequate definition of substantial completion 0.82 Delay to furnish and deliver the site to the contractor by owner 0.79 Change orders by owner during construction 0.90
 2 Poor site management and supervision by contractor 0.76 Change orders by owner during construction 0.80 Change orders by owner during construction 0.78 Underestimation of time for completion 0.88
 3 Difficulties in financing project by contractor 0.75 Underestimation of time for completion 0.79 Underestimation of time for completion 0.78 Underestimation of cost of projects 0.87
 4 Unqualified workforce 0.75 Effects of subsurface conditions (e.g. soil, high water table, etc.) 0.79 Underestimation of cost of projects 0.77 Delay to furnish and deliver the site to the contractor by owner 0.87
 5 Change orders by owner during construction 0.74 Delay to furnish and deliver the site to the contractor by owner 0.77 Late in revising and approving design documents by owner 0.77 Effects of subsurface conditions (e.g. soil, high water table, etc.) 0.87
 6 Underestimation of cost of projects 0.73 Insufficient Feasibility studies and survey before investment 0.76 Difficulties in financing project by contractor 0.77 Inadequate definition of substantial completion 0.86
 7 Poor qualification of the contractors technical staff 0.73 Delay to furnish and deliver the site to the contractor by owner 0.74 Slow decision making 0.76 Insufficient Feasibility studies and survey before investment 0.84
 8 Effects of subsurface conditions (e.g. soil, high water table, etc.) 0.73 Underestimation of cost of projects 0.74 Delays in sub-contractors work 0.76 Unqualified workforce 0.84
 9 Underestimation of time for completion 0.71 Unqualified workforce 0.74 Inadequate definition of substantial completion 0.75 Delay in obtaining permits from municipality 0.84
10 Delay in obtaining permits from municipality 0.70 Low productivity and efficiency of equipment 0.74 Poor communication and coordination by owner and other parties 0.75 Slow decision making 0.83

RII and ranking of categories of causes of delay

Category Clients Consultants Contractors Overall
RII Rank RII Rank RII Rank RII Rank
Client-related causes 0/563 5 0/634 2 0/651 1 0/716 1
Contractor-related causes 0/654 1 0/639 1 0/501 7 0/698 3
Consultant-related causes 0/601 2 0/480 7 0/572 6 0/645 7
Design-related causes 0/561 6 0/567 6 0/585 4 0/666 5
Material-related causes 0/566 4 0/596 3 0/613 3 0/690 4
Labor and equipment category causes 0/599 3 0/571 4 0/632 2 0/701 2
External causes 0/546 7 0/569 5 0/584 5 0/662 6

Analysis of variance (ANOVA)

Sum of squares df Mean square F Sig.
Between groups 0.009 6 0.001 0.685 0.665
Within groups 0.030 14 0.002
Total 0.039 20

Pearson’s correlation

Clients Consultants Contractors
Clients
Pearson correlation 1 0.135 −0.672
Sig. (2-tailed) 0.773 0.028
N 7 7 7
Consultants
Pearson correlation 0.135 1 −0.002
Sig. (2-tailed) 0.773 0.997
N 7 7 7
Contractors
Pearson correlation −0.672 −0.002 1
Sig. (2-tailed) 0.028 0.997
N 7 7 7

Type of delay analysis techniques and explanation of pros and cons of each method

A variety of delay analysis techniques
Techniques type Techniques description Pros of the technique Cons of the technique
1. Pervasive influence Technique A simple method for analysis When the calculation is not accurate, it has many applications 1. Ignoring simultaneous time delays
2. Rights resulted from delays are shown with great exaggeration
3. It has many opponents
2. Bar chart or Gant chart technique (Clark, 2006; Alkass et al., 1996) It identifies critical activities implemented in its time table and compares them with critical activities in planed schedule 1. Assesses delays impact on overall project
2. It indicates the cause and responsibility for the delays that effect on the completion date of the project
3. In the case of availability of planned and real schedule, it is cheap method
1. Because the schedule program is not based on CPM calculation, this method does not include information like use of flotation, and changes of project schedule and also changes made in the critical path
2. The method is time consuming and should be done based on judgment, research and professional evaluation
3. Collapse technique or (but because) (Clark, 2006; Alkass et al., 1996) It uses CPM format and so the result is the difference between the time completion of the construction and modified schedule
This technique is applicable at the end of the project, when there is no other possibility for delay compensation
1. This is the best method when the delay analysis needs to be revised
2. This technique is very good for projects that are linear in nature and structure and the events are considered in As built schedule instead of planned schedule
3. Simplicity of comparison is the advantage of this method to project manager’s presentations
1. There is no possibility of implementing the As built program as predicted
2. In complex situations where many events occur simultaneously in project or As Built schedule in detail not available, this method does not show the required efficiency
4. Critical path method and adjusted as built CPM technique This technique uses the CPM, and development As Built schedule
This technique is similar to the Net Impact Technique, for Both techniques show only the net effect of all the claimed delay in projects time completion
This technique is better than Net Impact Technique and if there is information, such as As-Built program, analysis of the mentioned technique, could be done easily 1. Delays types are not be checked carefully
2. There is no possibility for analyzing the delays at the same time
3. Delay events that cause claim in the project may be show in the schedule but most likely is not clear and not be on the critical path
5. Time impact technique (Clark, 2006; Alkass et al., 1996) In this technique the principles of Critical Path Method are used and the effects of delays in the project schedule are evaluated through periodic and usually every day analysis. This technique is similar to Snapshot analysis, by this difference that Time Impact Technique focuses on the delay or delay certain events, not a period of time including all delays. This technique is an advanced mode of Impacted As-planned Technique This technique provides a systematic and scientific method to quantify the impact of delays in project 1. It is the most time consuming and most expensive method
2. If the information is invalid, the results of the analysis may be very different from reality
3. It has not the ability to determine the exact type of delay, before the analysis completion
4. Delay activity is analyzed separately and therefore, the impact of simultaneous delays in project, when analysis is done is not traceable and these attitudes are unrealistic
5. The accuracy of this method is subjected to the number of analysis that can be done, and if there are a lot of events that cause delays in the analysis, the use of this technique is very difficult and time consuming
6. Global impact technique (Kartam, 1999) In this technique, the whole projects delay is achieved by collecting all delays which are applied in completion of activities Simplicity of the analysis and not requiring for activities and relationships in the schedules are the notable advantages of this technique 1. Ignoring the simultaneous delays
2. The lack of accurate determination of delays and the inability to determine the critical path and float activities
7. Net impact technique (Stumpf, 2000) This technique only manifests the whole claimed delays through bar graph. In this technique, all the activities with delays are being considered, but only net effect of created delays in the activities, by considering the delays being simultaneous are applied 1. Using this technique, all the delays, non-consistency in performing activities, work orders and suspensions are drown in As Built scheduling and just net effect of all delays is calculated
2. Consider the simultaneous delays
1. It has not ability to exact determination of the types of delays
2. As long as the networks facility is not used, the real impact of delay on the full completion of the project is difficult to determine
8. Impacted as-planned technique (Keane and Caletka, 2008) This technique uses CPM scheduling model and only includes delays that are related to one of the parties (Depending on whether the delays analyst, from which side) 1. This technique offers a relatively good method that with limited information collected from the beginning of the project is able to analyze the occurred delay
2. One of the major advantages of this technique that can be noted is to determine the type of delays during analysis which performed simply and at high speed
1. This technique is not considered change in CPM scheduling, during project execution and delays in As-planned scheduling in one step are applied which leads to achieve unrealistic results, because probably the critical path changes during project execution
2. This technique cannot be considered as an impartial analysis
9. Collapsed as-built technique (Keane and Caletka, 2008) Like impacted As-planned technique, this technique uses CPM scheduling model and in order to overcome some shortcomings, when doing analysis, it uses As Built schedule, therefore at first, it is necessary that all delays caused by the parties involved in the project, be identified and applied This method is selected when the contractor has not an acceptable schedule (during project execution) or when any pre-programmed schedule in the contract is not needed 1. No change in the CPM scheduling, during project execution
2. Delays related to one of the parties involved in the project that have taken place, altogether and in one step removed from the As Built schedule that would cause to achieve unrealistic results
3. This technique has not any reliance and dependence on As-planned schedule as the basis for analysis
10. Sectional technique or timeframe or snapshot technique In this technique, independent and consecutive time periods in As-planned schedule (Primary Schedule) are used for imposing delays, based on what actually happened, in each of the above-mentioned periods. This technique is formed on the basis of As-planned schedule, As Built schedule and any other review schedule that is created during the projects execution This technique proposes a systematic, impartially and fairly accurate way for the quantification of the delays in the project, which is moving, on an ongoing basis (based on As-planned schedule)
This method considers simultaneous delays and indicated the impact of delays on the basis of time and CPM schedule based on what has really happened at that time period and it has been known as a complete and accurate technique for analyze delays
1. The types of delay is not clear in this technique and it is necessary to do other analyses on the results in order to identify the share of each party of delays
2. This technique is very time consuming
11. Isolated delay type technique This technique, tries to consider all three principles (Categorization of delays, considering simultaneous delays, analysis of delays in real-time), in the way of performed analysis which require the presence of an event log and accurate documentation of information system from the beginning of the project. Albeit, the accuracy of this analysis is subjected to the number of performed analyses

Factors influencing on choosing a suitable method to analyze delay, according to SCL protocol and AACEI RP-FSA

AACEI RP-FSA SCL protocol
Contract requirements Conditions of contract
Analysis purposes Nature of the causal relations of the events in log project
The availability and reliability of data sources The rate of claims value
The complexity of the claims Existing time to analyze
Time and budget available to analyze Access to records
Access to experts of timing legal analysis Access to scheduling information
Legal services of the voting The planner’s skills and familiarity with project
Previous methods of parties
Legal requirements

Accommodation and evaluation of Tables V and VI

Analysis based on several schedule program
The rate of use in complicated and valuable financial claims Requires the time and budget available to analyze project Requires the sources of information and records of the project to analyze Rate of acceptance from the legal services of the voting court Possibility of using simultaneous delay Analysis based on CPM As-Planned Schedule As-Built Schedule As-Projected Schedule Rate of acceptability regarding its use
Techniques type High Low High Low High Low High Low Description High Low
1. Pervasive influence technique * * * * This method is simple and ignores simultaneous delays and exaggerates in showing them and it has many opponents * *
2. Bar chart or Gant chart technique * * * * This technique is not aware of those events occurring during the project like flooted consumption, scheduling changes and critical path and so it has problem in needed accuracy * * * * * *
3. Collapse technique or (but because) * * * * In complex conditions in which so many events have occurred simultaneously in the project and or as built schedule is not available with details, this method will not have necessary efficiency * * *
4. Critical path method and adjusted as built CPM technique * Delay events that caused claim, may not be shown in scheduling, but they are more likely not clear and definite and may not be on critical path * * * * *
5. Time Impact technique * * * * This method is systematic, unbiased and relatively accurate and the analysis is severely made the influence of the basic program and programmer skill with the project. The accuracy of this method is subjected to the number of performed analysis and in the case of the presence of high amount of events causing delay in this analysis, use of this technique is so difficult and time consuming * * * *
6. Global impact technique * * * * The lack of accurate determination of created delayed and disability in determining the critical path and contentment activities and exaggeration in displaying delay and rejection of this method from the court * *
7. Net impact technique * * * * Though it uses simultaneous delays, but it has not the ability to follow the delay accurately and the delay is being exaggerated and when the network is not being used, determination of delay on project completion time properly is hard * * *
8. Impacted as-planned technique * * * In this method, the analyst can add just one side of contract delays to schedule program in any step and examine its impact, therefore it is unfair method * * **
9. Collapsed as-built technique * * * * Regarding that this method does not consider those delays done in project administration and change in resource allocation and schedule steps, the analyses could sometimes lead to unacceptable results * *
10. Sectional technique or timeframe or snapshot technique * * * * This technique proposes a systematic, unbiased, and relatively exact method to quantify performed delays in the project and is considered as a complete and accurate technique for delays but is so time consuming * * * * * *
11. Isolated delay type technique * * * * This technique proposes a systematic, unbiased, and relatively exact method to quantify performed delays in the project and is considered as a complete and accurate technique for delays but is so time consuming * * * * * *

The method of choosing the most appropriate technique based on the nature of project and the value of delays

Type of project The rate of delays The volume of available documentation Time duration of dealing with delay Expense of dealing with delay The proposed method for the analysis of delays
Classification of delayed projects in construction industry of Iran
Small projects: Implementation: in less than one year amounted to less than 30 million dollars Low to moderate High (The rate of delays More than 30 percent of the project) Low (simplified) Low Low to moderate 1. Pervasive influence Technique
4. Critical path method and adjusted as-built CPM technique
High (The rate of delays up to 30 percent of the project)
Medium projects: Implementation: 1 to 3 years amounted to between 30 and 50 million dollars Low to moderate (The rate of delays up to 30 percent of the project) Low to moderate Moderate (less than 6 months) High 2. Bar chart or Gant chart technique
5. Time impact technique
6. Global impact technique
7. Net impact technique
High
(The rate of delays More than 30 percent of the project)
Large-scale projects: Implementation: over three years amounted to more than 50 million dollars Low to moderate (The rate of delays up to 30 percent of the project) A lot of (complicated) over 50 Ledger High (more than 6 months to one year) Very high 3. Collapse technique
8. Impacted as-planned technique
9. Collapsed as-built technique
10. Sectional technique
11. Isolated delay type technique
High
(The rate of delays More than 30 percent of the project)

List of causes of delay categorized into seven groups

No. Case of delay Group
 1 Change orders by owner during construction Client
 2 Underestimation of time for completion Client
 3 Underestimation of cost of projects Client
 4 Delay to furnish and deliver the site to the contractor by owner Client
 5 Inadequate definition of substantial completion Client
 6 Insufficient feasibility studies and survey before investment Client
 7 Slow decision making Client
 8 Poor communication and coordination by owner and other parties Client
 9 Late in revising and approving design documents by owner Client
10 Type of project bidding and award (negotiation, lowest bidder) Client
11 Type of construction contract (Turnkey, construction only) Client
12 Suspension of work by owner Client
13 Ineffective delay penalties by owner Client
14 Unavailability of incentives for contractor for finishing ahead of schedule Client
15 Delay in approving shop drawings and sample materials Client
16 Delay in finance and payments of completed work by owner Client
17 Poor supervision Client
18 Low bid Client
19 Delays in inspection and testing of work Client
20 Difficulties in financing project by contractor Contractor
21 Delays in sub-contractors work Contractor
22 Poor qualification of the contractors technical staff Contractor
23 Poor site management and supervision by contractor Contractor
24 Rework due to errors during construction Contractor
25 Ineffective planning and scheduling of project by contractor Contractor
26 Inadequate contractor experience Contractor
27 Frequent change of sub-contractors because of their inefficient work Contractor
28 Poor communication and coordination by contractor with other parties Contractor
29 Conflicts in sub-contractors schedule in execution of project Contractor
30 Improper construction methods implemented by contractor Contractor
31 Conflicts between contractor and other parties (consultant and owner) Contractor
32 Delay in site mobilization Contractor
33 Inadequate experience of consultant Consultant
34 Delay in performing inspection and testing by consultant Consultant
35 Poor communication/coordination between consultant and other parties Consultant
36 Delay in approving major changes in the scope of work by consultant Consultant
37 Inflexibility (rigidity) of consultant Consultant
38 Late in reviewing and approving design documents by consultant Consultant
39 Conflicts between consultant and design engineer Consultant
40 Unclear and inadequate details in drawings Consultant
41 Quality assurance/control Consultant
42 Mistakes and discrepancies in design documents Design
43 Delays in producing design documents Design
44 Complexity of project design Design
45 Insufficient data collection and survey before design Design
46 Unclear and inadequate details in drawings Design
47 Misunderstanding of owner’s requirements by design engineer Design
48 Inadequate design-team experience Design
49 Un-use of advanced engineering design software Design
50 Shortage of construction materials in market Material
51 Delay in material delivery Material
52 Changes in material types and specifications during construction Material
53 Damage of sorted material while they are needed urgently Material
54 Delay in manufacturing special building materials Material
55 Late procurement of materials Material
56 Late in selection of finishing materials due to availability of many types in market Material
57 Escalation of material prices Material
58 Unqualified workforce Labor and equipment
59 Low productivity level of labors Labor and equipment
60 Shortage of labors Labor and equipment
61 Low productivity and efficiency of equipment Labor and equipment
62 Equipment availability and failure Labor and equipment
63 Low level of equipment-operator’s skill Labor and equipment
64 Personal conflicts among labors Labor and equipment
65 Lack of high-technology mechanical equipment Labor and equipment
66 Effects of subsurface conditions (e.g. soil, high water table, etc.) External factor
67 Delay in obtaining permits from municipality External factor
68 Effect of social and cultural factors External factor
69 Weather effect (hot, rain, etc.) External factor
70 Changes in government regulations and laws External factor
71 Unavailability of utilities in site (such as, water, electricity, telephone, etc.) External factor
72 Traffic control and restriction at job site External factor
73 Accident during construction External factor
74 Differing site (ground) conditions External factor
75 Delay in providing services from utilities (such as water, electricity) External factor
76 Fluctuations in cost/ currency External factor
77 Delay in performing final inspection and certification by a third party External factor
78 Force majeure as war, revolution, riot, strike, and earthquake, etc. External factor

The main causes of delays in each category specified and have been ranked based on RII

Criteria weights RII Rank
V.L L M H V.H
Delay group No. Factor of delay 1. 2. 3. 4. 5.
Client comments
1. Employer delays 1/1 Change orders by owner during construction 4 8 12 16 22 0/74 1
2/1 Underestimation of time for completion 3 12 13 16 18 0/71 3
3/1 Underestimation of cost of projects 5 6 14 18 19 0/73 2
4/1 Delay to furnish and deliver the site to the contractor by owner 9 8 13 15 17 0/67 5
5/1 Inadequate definition of substantial completion 8 13 10 15 16 0/66 8
6/1 Insufficient feasibility studies and survey before investment 6 12 13 17 14 0/67 6
7/1 Slow decision making 7 10 16 14 15 0/66 7
8/1 Poor communication and coordination by owner and other parties 5 11 13 17 16 0/69 4
9/1 Late in revising and approving design documents by owner 9 16 14 11 12 0/6 10
10 Type of project bidding and award (negotiation, lowest bidder) 9 14 13 15 11 0/62 9
11/1 Type of construction contract (Turnkey, construction only) 14 12 15 12 9 0/57 11
12 Suspension of work by owner 15 19 13 7 8 0/52 13
13/1 Ineffective delay penalties by owner 14 22 7 10 9 0/53 12
14/1 Unavailability of incentives for contractor for finishing ahead of schedule 18 24 9 6 5 0/46 14
15/1 Delay in approving shop drawings and sample materials 22 25 5 4 6 0/43 15
16/1 Delay in finance and payments of completed work by owner 30 19 5 4 4 0/38 16
17/1 Poor supervision 31 20 6 3 2 0/36 17
18/1 Low bid 29 26 4 2 1 0/34 18
19/1 Delays in inspection and testing of work 30 27 2 1 2 0/34 19
2. Contractor delays 2/1 Difficulties in financing project by contractor 5 6 9 20 22 0/75 3
2/2 Delays in sub-contractors work 4 7 8 19 24 0/77 1
2/3 Poor qualification of the contractors technical staff 6 8 9 18 21 0/73 4
2/4 Poor site management and supervision by contractor 4 5 10 24 19 0/76 2
2/5 Rework due to errors during construction 6 9 12 18 17 0/7 5
2/6 Ineffective planning and scheduling of project by contractor 7 9 13 17 16 0/68 6
2/7 Inadequate contractor experience 8 13 10 16 15 0/65 9
2/8 Frequent change of sub-contractors because of their inefficient work 6 11 14 17 14 0/67 7
2/9 Poor communication and coordination by contractor with other parties 5 10 19 16 12 0/66 8
2/10 Conflicts in sub-contractors schedule in execution of project 10 11 17 14 10 0/61 10
2/11 Improper construction methods implemented by contractor 16 14 12 11 9 0/55 11
2/12 Conflicts between contractor and other parties (consultant and owner) 17 24 6 8 7 0/48 12
2/13 Delay in site mobilization 17 23 10 6 6 0/47 13
3. Consultant delays 3/1 Inadequate experience of consultant 7 9 13 15 18 0/69 1
3/2 Delay in performing inspection and testing by consultant 9 10 11 17 15 0/66 2
3/3 Poor communication/coordination between consultant and other parties 10 11 9 15 17 0/66 3
3/4 Delay in approving major changes in the scope of work by consultant 12 10 11 14 15 0/63 4
3/5 Inflexibility (rigidity) of consultant 13 9 10 16 14 0/63 5
3/6 Late in reviewing and approving design documents by consultant 11 14 9 15 13 0/62 6
3/7 Conflicts between consultant and design engineer 15 18 8 10 11 0/55 7
3/8 Unclear and inadequate details in drawings 17 20 8 9 8 0/51 8
3/9 Quality assurance/control 18 24 7 7 6 0/47 9
4. Design delays 4/1 Mistakes and discrepancies in design documents 8 9 12 17 16 0/68 1
4/2 Delays in producing design documents 8 11 10 18 15 0/67 2
4/3 Complexity of project design 9 10 13 16 14 0/65 3
4/4 Insufficient data collection and survey before design 16 12 10 13 11 0/57 5
4/5 Unclear and inadequate details in drawings 12 15 14 11 10 0/57 4
4/6 Misunderstanding of owner’s requirements by design engineer 19 17 9 8 9 0/51 6
4/7 Inadequate design-team experience 21 23 5 7 6 0/45 7
4/8 Un-use of advanced engineering design software 28 22 3 5 4 0/39 8
5. Material delays 5/1 Shortage of construction materials in market 7 7 13 17 18 0/7 1
5/2 Delay in material delivery 9 11 12 14 16 0/65 2
5/3 Changes in material types and specifications during construction 12 9 10 17 14 0/64 3
5/4 Damage of sorted material while they are needed urgently 16 15 6 12 13 0/57 4
5/5 Delay in manufacturing special building materials 16 17 8 11 10 0/54 5
5/6 Late procurement of materials 20 17 5 11 9 0/51 6
5/7 Late in selection of finishing materials due to availability of many types in market 18 20 6 10 8 0/5 7
5/8 Escalation of material prices 25 23 5 4 5 0/41 8
6. Labor and equipment delays 6/1 Unqualified workforce 4 7 11 19 21 0/75 1
6/2 Low productivity level of labors 6 12 7 18 19 0/7 2
6/3 Shortage of labors 7 15 6 16 18 0/67 3
6/4 Low productivity and efficiency of equipment 14 14 7 12 15 0/6 4
6/5 Equipment availability and failure 13 17 6 14 12 0/58 5
6/6 Low level of equipment-operator’s skill 16 19 8 9 10 0/53 6
6/7 Personal conflicts among labors 18 21 6 8 9 0/5 7
6/8 Lack of high-technology mechanical equipment 24 19 5 6 8 0/45 8
7. External delays 7/1 Effects of subsurface conditions (e.g. soil, high water table, etc.) 7 6 10 19 20 0/73 1
7/2 Delay in obtaining permits from municipality 6 9 11 18 18 0/71 2
7/3 Effect of social and cultural factors 11 8 10 17 16 0/66 3
7/4 Weather effect (hot, rain, etc.) 8 9 16 15 14 0/66 4
7/5 Changes in government regulations and laws 12 14 11 12 13 0/6 5
7/6 Unavailability of utilities in site (such as, water, electricity, telephone, etc.) 14 15 12 11 10 0/56 6
7/7 Traffic control and restriction at job site 16 14 12 9 11 0/55 7
7/8 Accident during construction 15 19 11 7 10 0/53 8
7/9 Differing site (ground) conditions 17 21 8 7 9 0/5 9
7/10 Delay in providing services from utilities (such as water, electricity) 21 23 8 6 4 0/44 10
7/11 Fluctuations in cost/currency 25 23 7 4 3 0/4 11
7/12 Delay in performing final inspection and certification by a third party 28 22 5 3 4 0/38 12
7/13 Force Majeure as war, revolution, riot, strike, and earthquake, etc. 25 27 4 3 3 0/38 13
Consultant comments (55)
1. Employer delays 1/1 Change orders by owner during construction 2 7 5 21 20 0/78 2
2/1 Underestimation of time for completion 3 6 4 23 19 0/78 3
3/1 Underestimation of cost of projects 4 7 4 18 22 0/77 4
4/1 Delay to furnish and deliver the site to the contractor by owner 2 4 10 19 20 0/79 1
5/1 Inadequate definition of substantial completion 4 6 8 20 17 0/75 7
6/1 Insufficient Feasibility studies and survey before investment 5 7 9 15 19 0/73 9
7/1 Slow decision making 3 4 11 19 18 0/76 6
8/1 Poor communication and coordination by owner and other parties 4 7 9 16 19 0/74 8
9/1 Late in revising and approving design documents by owner 3 6 7 20 19 0/77 5
10 Type of project bidding and award (negotiation, lowest bidder) 4 8 11 16 16 0/72 10
11/1 Type of construction contract (Turnkey, construction only) 8 10 9 13 15 0/66 11
12 Suspension of work by owner 9 13 8 14 11 0/62 12
13/1 Ineffective delay penalties by owner 11 15 6 11 12 0/59 13
14/1 Unavailability of incentives for contractor for finishing ahead of schedule 12 21 9 7 6 0/51 14
15/1 Delay in approving shop drawings and sample materials 17 20 3 6 9 0/49 15
16/1 Delay in finance and payments of completed work by owner 21 15 6 7 6 0/46 16
17/1 Poor supervision 22 20 7 3 3 0/4 17
18/1 Low bid 24 21 5 3 2 0/37 18
19/1 Delays in inspection and testing of work 26 21 4 2 2 0/36 19
2. Contractor delays 2/1 Difficulties in financing project by contractor 3 4 10 19 19 0/77 1
2/2 Delays in sub-contractors work 3 5 9 20 18 0/76 2
2/3 Poor qualification of the contractors technical staff 4 6 11 15 19 0/74 3
2/4 Poor site management and supervision by contractor 3 11 5 21 15 0/72 4
2/5 Rework due to errors during construction 5 9 12 15 14 0/69 5
2/6 Ineffective planning and scheduling of project by contractor 7 14 9 13 12 0/63 7
2/7 Inadequate contractor experience 10 14 8 12 11 0/6 9
2/8 Frequent change of sub-contractors because of their inefficient work 8 12 11 14 10 0/62 8
2/9 Poor communication and coordination by contractor with other parties 8 10 10 16 11 0/64 6
2/10 Conflicts in sub-contractors schedule in execution of project 17 9 7 13 9 0/56 11
2/11 Improper construction methods implemented by contractor 18 6 10 11 10 0/56 10
2/12 Conflicts between contractor and other parties (consultant and owner) 20 8 9 9 9 0/52 12
2/13 Delay in site mobilization 17 18 6 7 7 0/49 13
3. Consultant delays 3/1 Inadequate experience of consultant 10 11 15 9 10 0/59 2
3/2 Delay in performing inspection and testing by consultant 12 10 8 12 13 0/61 1
3/3 Poor communication/coordination between consultant and other parties 15 14 7 10 9 0/54 3
3/4 Delay in approving major changes in the scope of work by consultant 16 12 12 7 8 0/52 5
3/5 Inflexibility (rigidity) of consultant 15 12 13 7 8 0/53 4
3/6 Late in reviewing and approving design documents by consultant 24 15 9 4 3 0/41 6
3/7 Conflicts between consultant and design engineer 25 17 6 3 4 0/4 7
3/8 Unclear and inadequate details in drawings 26 19 5 3 2 0/37 8
3/9 Quality assurance/control 26 22 4 2 1 0/35 9
4. Design delays 4/1 Mistakes and discrepancies in design documents 5 7 13 16 14 0/7 1
4/2 Delays in producing design documents 6 9 12 15 13 0/67 2
4/3 Complexity of project design 9 10 10 14 12 0/64 3
4/4 Insufficient data collection and survey before design 16 9 9 10 11 0/57 5
4/5 Unclear and inadequate details in drawings 14 12 7 12 10 0/57 4
4/6 Misunderstanding of owner’s requirements by design engineer 15 17 7 9 7 0/51 6
4/7 Inadequate design-team experience 17 20 6 7 5 0/47 7
4/8 Un-use of advanced engineering design software 19 24 5 4 3 0/41 8
5. Material delays 5/1 Shortage of construction materials in market 4 7 13 14 17 0/72 1
5/2 Delay in material delivery 4 10 9 17 15 0/71 2
5/3 Changes in material types and specifications during construction 8 11 7 15 14 0/66 3
5/4 Damage of sorted material while they are needed urgently 7 17 7 14 10 0/61 5
5/5 Delay in manufacturing special building materials 9 11 9 12 14 0/64 4
5/6 Late procurement of materials 16 12 7 9 11 0/55 6
5/7 Late in selection of finishing materials due to availability of many types in market 16 17 6 9 7 0/51 7
5/8 Escalation of material prices 24 21 4 4 2 0/38 8
6. Labor and equipment delays 6/1 Unqualified workforce 9 7 10 14 15 0/67 1
6/2 Low productivity level of labors 7 14 7 13 14 0/65 2
6/3 Shortage of labors 8 16 8 11 12 0/61 3
6/4 Low productivity and efficiency of equipment 14 14 8 9 10 0/55 6
6/5 Equipment availability and failure 12 16 5 13 9 0/57 4
6/6 Low level of equipment-operator’s skill 11 18 4 14 8 0/56 5
6/7 Personal conflicts among labors 16 17 5 8 9 0/52 7
6/8 Lack of high-technology mechanical equipment 19 21 4 6 5 0/44 8
7. External delays 7/1 Effects of subsurface conditions (e.g. soil, high water table, etc.) 5 6 12 14 18 0/72 2
7/2 Delay in obtaining permits from municipality 6 6 11 15 17 0/71 3
7/3 Effect of social and cultural factors 5 4 9 19 18 0/75 1
7/4 Weather effect (hot, rain, etc.) 8 6 11 14 16 0/69 4
7/5 Changes in government regulations and laws 11 8 9 14 13 0/64 6
7/6 Unavailability of utilities in site (such as, water, electricity, telephone, etc.) 7 9 10 15 14 0/67 5
7/7 Traffic control and restriction at job site 13 11 9 12 10 0/58 7
7/8 Accident during construction 15 17 6 9 8 0/52 8
7/9 Differing site (ground) conditions 18 16 8 6 7 0/48 9
7/10 Delay in providing services from utilities (such as water, electricity) 21 19 6 5 4 0/43 10
7/11 Fluctuations in cost/ currency 21 20 6 5 3 0/41 11
7/12 Delay in performing final inspection and certification by a third party 26 18 5 3 3 0/38 12
7/13 Force Majeure as war, revolution, riot, strike, and earthquake, etc. 25 21 3 4 2 0/37 13
Contractor comments (55)
1. Employer delays 1/1 Change orders by owner during construction 3 6 5 19 25 0/8 2
2/1 Underestimation of time for completion 4 5 8 14 27 0/79 3
3/1 Underestimation of cost of projects 6 7 5 19 21 0/74 6
4/1 Delay to furnish and deliver the site to the contractor by owner 3 6 9 18 22 0/77 4
5/1 Inadequate definition of substantial completion 1 3 9 22 23 0/82 1
6/1 Insufficient feasibility studies and survey before investment 4 8 5 20 21 0/76 5
7/1 Slow decision making 6 11 3 22 16 0/71 8
8/1 Poor communication and coordination by owner and other parties 8 12 6 16 16 0/67 10
9/1 Late in revising and approving design documents by owner 6 10 3 20 19 0/72 7
10 Type of project bidding and award (negotiation, lowest bidder) 7 12 6 15 18 0/69 9
11/1 Type of construction contract (Turnkey, construction only) 5 16 12 10 15 0/65 11
12 Suspension of work by owner 13 13 9 11 12 0/59 12
13/1 Ineffective delay penalties by owner 14 15 11 13 5 0/53 15
14/1 Unavailability of incentives for contractor for finishing ahead of schedule 22 8 4 14 10 0/54 14
15/1 Delay in approving shop drawings and sample materials 17 17 6 8 10 0/52 17
16/1 Delay in finance and payments of completed work by owner 9 24 7 8 10 0/55 13
17/1 Poor supervision 11 21 11 8 7 0/53 16
18/1 Low bid 15 16 14 7 6 0/51 18
19/1 Delays in inspection and testing of work 15 17 15 8 3 0/49 19
2. Contractor delays 2/1 Difficulties in financing project by contractor 16 9 12 6 15 0/58 2
2/2 Delays in sub-contractors work 14 13 18 3 10 0/54 6
2/3 Poor qualification of the contractors technical staff 12 13 11 14 8 0/58 3
2/4 Poor site management and supervision by contractor 18 14 13 5 8 0/5 7
2/5 Rework due to errors during construction 16 11 12 11 8 0/54 5
2/6 Ineffective planning and scheduling of project by contractor 16 10 7 12 13 0/59 1
2/7 Inadequate contractor experience 17 9 9 12 11 0/57 4
2/8 Frequent change of sub-contractors because of their inefficient work 23 9 11 6 9 0/49 8
2/9 Poor communication and coordination by contractor with other parties 28 18 3 3 6 0/4 12
2/10 Conflicts in sub-contractors schedule in execution of project 16 25 4 5 8 0/48 9
2/11 Improper construction methods implemented by contractor 17 27 3 6 5 0/44 10
2/12 Conflicts between contractor and other parties (consultant and owner) 20 22 12 1 3 0/41 11
2/13 Delay in site mobilization 28 16 7 3 4 0/39 13
3. Consultant delays 3/1 Inadequate experience of consultant 7 10 4 18 19 0/71 2
3/2 Delay in performing inspection and testing by consultant 11 9 5 18 15 0/66 4
3/3 Poor communication/coordination between consultant and other parties 5 9 11 14 19 0/71 1
3/4 Delay in approving major changes in the scope of work by consultant 6 14 8 15 15 0/67 3
3/5 Inflexibility (rigidity) of consultant 13 18 6 9 12 0/56 5
3/6 Late in reviewing and approving design documents by consultant 18 20 5 9 6 0/48 7
3/7 Conflicts between consultant and design engineer 15 18 13 8 4 0/49 6
3/8 Unclear and inadequate details in drawings 19 20 10 5 4 0/44 8
3/9 Quality assurance/control 23 18 8 5 4 0/42 9
4. Design delays 4/1 Mistakes and discrepancies in design documents 12 12 6 11 17 0/63 3
4/2 Delays in producing design documents 17 5 6 10 20 0/64 2
4/3 Complexity of project design 17 12 2 11 16 0/59 4
4/4 Insufficient data collection and survey before design 5 8 13 15 17 0/71 1
4/5 Unclear and inadequate details in drawings 19 10 3 10 16 0/58 5
4/6 Misunderstanding of owner’s requirements by design engineer 15 17 3 10 13 0/56 6
4/7 Inadequate design-team experience 15 19 4 7 13 0/54 7
4/8 Un-use of advanced engineering design software 27 13 7 4 7 0/43 8
5. Material delays 5/1 Shortage of construction materials in market 8 8 6 16 20 0/71 3
5/2 Delay in material delivery 9 6 7 14 22 0/72 2
5/3 Changes in material types and specifications during construction 5 12 9 15 17 0/69 4
5/4 Damage of sorted material while they are needed urgently 9 3 9 18 19 0/72 1
5/5 Delay in manufacturing special building materials 14 15 7 12 10 0/56 6
5/6 Late procurement of materials 9 18 10 12 9 0/58 5
5/7 Late in selection of finishing materials due to availability of many types in market 15 21 7 6 9 0/51 7
5/8 Escalation of material prices 28 15 5 4 6 0/41 8
6. Labor and equipment delays 6/1 Unqualified workforce 4 10 8 13 23 0/74 1
6/2 Low productivity level of labors 9 6 9 13 21 0/71 3
6/3 Shortage of labors 12 3 5 19 19 0/7 4
6/4 Low productivity and efficiency of equipment 7 1 11 23 16 0/74 2
6/5 Equipment availability and failure 11 9 10 14 14 0/64 5
6/6 Low level of equipment-operator’s skill 20 2 7 15 14 0/6 6
6/7 Personal conflicts among labors 20 11 5 11 11 0/54 7
6/8 Lack of high-technology mechanical equipment 26 16 10 5 1 0/39 8
7. External delays 7/1 Effects of subsurface conditions (e.g. soil, high water table, etc.) 2 4 10 21 21 0/79 1
7/2 Delay in obtaining permits from municipality 4 6 11 18 19 0/74 2
7/3 Effect of social and cultural factors 4 8 10 19 17 0/73 3
7/4 Weather effect (hot, rain, etc.) 7 11 7 14 19 0/69 4
7/5 Changes in government regulations and laws 9 8 8 15 18 0/69 5
7/6 Unavailability of utilities in site (such as, water, electricity, telephone, etc.) 18 13 4 8 15 0/56 6
7/7 Traffic control and restriction at job site 16 22 2 8 10 0/51 8
7/8 Accident during construction 16 13 10 8 11 0/55 7
7/9 Differing site (ground) conditions 18 17 8 8 7 0/49 9
7/10 Delay in providing services from utilities (such as water, electricity) 22 17 6 7 6 0/46 12
7/11 Fluctuations in cost/ currency 15 24 5 6 8 0/49 10
7/12 Delay in performing final inspection and certification by a third party 12 29 6 7 4 0/47 11
7/13 Force Majeure as war, revolution, riot, strike, and earthquake, etc. 20 25 5 4 4 0/42 13
Total views (175) of all three factors (62 clients, 55 consultants, 58 contractors)
1. Employer delays 1/1 Change orders by owner during construction 9 21 22 56 67 0/90 1
2/1 Underestimation of time for completion 10 23 25 53 64 0/88 2
3/1 Underestimation of cost of projects 15 20 23 55 62 0/87 3
4/1 Delay to furnish and deliver the site to the contractor by owner 14 18 32 52 59 0/87 4
5/1 Inadequate definition of substantial completion 13 22 27 57 56 0/86 5
6/1 Insufficient feasibility studies and survey before investment 15 27 27 52 54 0/84 6
7/1 Slow decision making 16 25 30 55 49 0/83 7
8/1 Poor communication and coordination by owner and other parties 17 30 28 49 51 0/82 8
9/1 Late in revising and approving design documents by owner 18 32 24 51 50 0/81 9
10 Type of project bidding and award (negotiation, lowest bidder) 20 34 30 46 45 0/78 10
11/1 Type of construction contract (Turnkey, construction only) 27 38 36 35 39 0/73 11
12 Suspension of work by owner 37 45 30 32 31 0/67 12
13/1 Ineffective delay penalties by owner 39 52 24 34 26 0/64 13
14/1 Unavailability of incentives for contractor for finishing ahead of schedule 52 53 22 27 21 0/58 14
15/1 Delay in approving shop drawings and sample materials 56 62 14 18 25 0/56 15
16/1 Delay in finance and payments of completed work by owner 60 58 18 19 20 0/54 16
17/1 Poor supervision 64 61 24 14 12 0/50 17
18/1 Low bid 68 63 23 12 9 0/47 18
19/1 Delays in inspection and testing of work 71 65 21 11 7 0/46 19
2. Contractor delays 2/1 Difficulties in financing project by contractor 24 19 31 45 56 0/82 1
2/2 Delays in sub-contractors work 21 25 35 42 52 0/81 2
2/3 Poor qualification of the contractors technical staff 22 27 31 47 48 0/80 3
2/4 Poor site management and supervision by contractor 25 30 28 50 42 0/77 4
2/5 Rework due to errors during construction 27 29 36 44 39 0/75 5
2/6 Ineffective planning and scheduling of project by contractor 30 33 29 42 41 0/74 6
2/7 Inadequate contractor experience 35 36 27 40 37 0/71 7
2/8 Frequent change of sub-contractors because of their inefficient work 37 32 36 37 33 0/70 8
2/9 Poor communication and coordination by contractor with other parties 41 38 32 35 29 0/66 9
2/10 Conflicts in sub-contractors schedule in execution of project 43 45 28 32 27 0/64 10
2/11 Improper construction methods implemented by contractor 51 47 25 28 24 0/60 11
2/12 Conflicts between contractor and other parties (consultant and owner) 57 54 27 18 19 0/55 12
2/13 Delay in site mobilization 62 57 23 16 17 0/53 13
3. Consultant delays 3/1 Inadequate experience of consultant 24 30 32 42 47 0/78 1
3/2 Delay in performing inspection and testing by consultant 32 29 24 47 43 0/75 2
3/3 Poor communication/coordination between consultant and other parties 30 34 27 39 45 0/75 3
3/4 Delay in approving major changes in the scope of work by consultant 34 36 31 36 38 0/71 4
3/5 Inflexibility (rigidity) of consultant 41 39 29 32 34 0/67 5
3/6 Late in reviewing and approving design documents by consultant 53 49 23 28 22 0/59 6
3/7 Conflicts between consultant and design engineer 55 53 27 21 19 0/56 7
3/8 Unclear and inadequate details in drawings 62 59 23 17 14 0/52 8
3/9 Quality assurance/control 67 64 19 14 11 0/48 9
4. Design delays 4/1 Mistakes and discrepancies in design documents 25 28 31 44 47 0/78 1
4/2 Delays in producing design documents 31 25 28 43 48 0/77 2
4/3 Complexity of project design 35 32 25 41 42 0/73 3
4/4 Insufficient data collection and survey before design 37 29 32 38 39 0/72 4
4/5 Unclear and inadequate details in drawings 45 37 24 33 36 0/67 5
4/6 Misunderstanding of owner’s requirements by design engineer 49 51 19 27 29 0/61 6
4/7 Inadequate design-team experience 53 62 15 21 24 0/57 7
4/8 Un-use of advanced engineering design software 74 59 15 13 14 0/48 8
5. Material delays 5/1 Shortage of construction materials in market 19 22 32 47 55 0/83 1
5/2 Delay in material delivery 22 27 28 45 53 0/81 2
5/3 Changes in material types and specifications during construction 25 32 26 47 45 0/77 3
5/4 Damage of sorted material while they are needed urgently 32 35 22 44 42 0/74 4
5/5 Delay in manufacturing special building materials 39 43 24 35 34 0/68 5
5/6 Late procurement of materials 45 47 22 32 29 0/64 6
5/7 Late in selection of finishing materials due to availability of many types in market 49 58 19 25 24 0/59 7
5/8 Escalation of material prices 77 59 14 12 13 0/47 8
6. Labor and equipment delays 6/1 Unqualified workforce 17 24 29 46 59 0/84 1
6/2 Low productivity level of labors 22 32 23 44 54 0/80 2
6/3 Shortage of labors 27 34 19 46 49 0/77 3
6/4 Low productivity and efficiency of equipment 35 29 26 44 41 0/74 4
6/5 Equipment availability and failure 36 42 21 41 35 0/70 5
6/6 Low level of equipment-operator’s skill 47 39 19 38 32 0/66 6
6/7 Personal conflicts among labors 54 49 16 27 29 0/60 7
6/8 Lack of high-technology mechanical equipment 69 56 19 17 14 0/50 8
7. External delays 7/1 Effects of subsurface conditions (e.g. soil, high water table, etc.) 14 16 32 54 59 0/87 1
7/2 Delay in obtaining permits from municipality 16 21 33 51 54 0/84 2
7/3 Effect of social and cultural factors 20 20 29 55 51 0/83 3
7/4 Weather effect (hot, rain, etc.) 23 26 34 43 49 0/79 4
7/5 Changes in government regulations and laws 32 30 28 41 44 0/75 5
7/6 Unavailability of utilities in site (such as, water, electricity, telephone, etc.) 39 37 26 34 39 0/70 6
7/7 Traffic control and restriction at job site 45 47 23 29 31 0/64 7
7/8 Accident during construction 46 49 27 24 29 0/62 8
7/9 Differing site (ground) conditions 53 54 24 21 23 0/58 9
7/10 Delay in providing services from utilities (such as water, electricity) 64 59 20 18 14 0/51 10
7/11 Fluctuations in cost/currency 61 67 18 15 14 0/51 11
7/12 Delay in performing final inspection and certification by a third party 66 69 16 13 11 0/48 12
7/13 Force majeure as war, revolution, riot, strike, and earthquake, etc. 70 73 12 11 9 0/45 13

Ranking the causes of delay and the ideas of decreasing and removing it

No. Category Alternative of decrease and remove of delays
1. Client-related causes  1. Accurate and realistic estimation of the time of the Project and the resources on hand (to decrease the causes of No. 2, 3, 5 in Table AI)
 2. Sufficient studies before investment and evaluation of the project before start of it (to decrease the causes of No. 1, 3, 5, 6, 7, 10, 11, 12, 15, 17 in Table AI)
 3. Lack of using poor executive principles due to hold low cost tenders (to decrease the causes of No. 14, 15, 17, 18, 19 in Table AI)
 4. Removing conflict and lack of delay (to decrease the causes of No. 4 in Table AI)
 5. Making correct decisions and in time (to decrease the causes of No. 4, 5, 7, 10, 12, 18 in Table AI)
 6. Not to change and excessive involve in initial assumptions and scope of the project (to decrease the causes of No. 1, 9 in Table AI)
 7. Reduce dispute among executive subordinates (to decrease the causes of No. 13, 14, 15, 17 in Table AI)
 8. Predict alternative financing in the case of deficiency (to decrease the causes of No. 3, 16, 19 in Table AI)
2. Labor and equipment category causes  9. Holding educational periods and safety justification in the workshop (to decrease the causes of No. 59, 63, 64 in Table AI)
10. The presence of incentive systems in the labor force
11. Allocation of skilled manpower and increase productivity (to decrease the causes of No. 58, 59, 60, 64 in Table AI)
12. Supply of new equipment and machinery (to decrease the causes of No. 62, 65 in Table AI)
13. Use of modern methods in the repair and maintenance of equipment during breakdowns and accidents (to decrease the causes of No. 65 in Table AI)
14. Considering standards in installation (to decrease the causes of No. 65 in Table AI)
15. Operating technology in mechanical devices and increasing the speed and efficiency and reduce errors (to decrease the causes of No. 61, 62, 63 in Table AI)
3. Contractor-related causes 16. Selection of sub-contractors based on competence rather than on low prices (to decrease the causes of No. 21, 22, 23, 24, 26, 27 in Table AI)
17. Considering safety points and HSE in Project (to decrease the causes of No. 21, 22, 24, 32 in Table AI)
18. Non-weak contractors in developing executive alternative of coping with sever territories (to decrease the causes of No. 22, 26 in Table AI)
19. The technical study and design schedule and planning by the contractor during the tender stage (to decrease the causes of No. 23, 24, 27, 29 in Table AI)
20. Provide timely statements (to decrease the causes of No. 29, 31 in Table AI)
21. Sub-contractors following of schedule (to decrease the causes of No. 21, 29 in Table AI)
4. Material-related causes 22. Timely selection in approval of resources of the materials and buying them (to decrease the causes of No. 52, 55, 56, 57 in Table AI)
23. Anticipation of the shortage of materials in the market and considering the solutions before the crisis and rising prices (to decrease the causes of No. 50, 55, 57 in Table AI)
24. Requesting a guideline formulated about the condition of maintaining the facilities and materials from manufacturers and suppliers (to decrease the causes of No. 51, 53, 54 in Table AI)
25. Prevention of crime and abuse of resources and materials while transit in workshop environment
5. Design-related causes 26. Use of advanced software engineering and design (to decrease the causes of No. 42, 44, 46, 47, 49 in Table AI)
27. Provide timely execution plans to contractor
(to decrease the causes of No. 45, 43 in Table AI)
6. External causes 28. No deficiency would be in the formulating contracts (to decrease the causes of No. 67, 70 in Table AI)
29. Considering referee of resolving discrepancy among workforces (to decrease the causes of No. 67, 70 in Table AI)
30. Financial limitation faced due to lack of allocation budget by government in the projects (to decrease the causes of no. 76 in Table AI)
31. Anticipation of international situation and prolong the negotiations with builders and track orders (to decrease the causes of No. 78 in Table AI)
32. Anticipation of prolonging orders because of office bureaucracy (to decrease the causes of No. 67 in Table AI)
33. Study and anticipation of regional bad weather conditions (to decrease the causes of No. 69 in Table AI)
34. Study on inflation and market fluctuations and presenting alternatives (to decrease the causes of No. 76 in Table AI)
35. Exchange rate forecasting because of the political regional climate and gold and oil price impact on it (to decrease the causes of No. 76, 78 in Table AI)
36. Considering the conditions of societies and their cultures and preventing regional and labor strikes (to decrease the causes of No. 68, 78 in Table AI)
37. Paying attention to allocating credits in 2nd half of the year by the government on public projects (to decrease the causes of No. 76 in Table AI)
7. Consultant-related causes 38. Accuracy in early studies and examining the feasibility of projects economic justification (to decrease the causes of No. 36, 41 in Table AI)
39. Timely providing design drawings and personating documents needed for next decision makings (to decrease the causes of No. 33, 34, 35, 38, 40 in Table AI)
40. High accuracy in evaluation and estimation of the volumes and work sums (to decrease the causes of No. 39, 40, 41 in Table AI)

References

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Further reading

AACE (2007), “International, AACE international recommended practice No. 29R-03”, Forensic Schedule Analysis, Published by the Society of Construction Low, Administrative Office, Wantage.

Badir, Y.F.M. and Kadir, M.R. (2002), “Industrialized building systems in Malaysia”, Journal of Architectural Engineering, Vol. 8 No. 1.

Desai, M. and Bhatt, R. (2013), “A Methodology for ranking of causes of delay for residential construction projects in Indian Context”, International Journal of Emerging Technology and Advanced Engineering, Vol. 3 No. 3, pp. 396-404.

Frimpong, Y. and Oluwoye, J. (2003), “Significant factors causing delay and cost overruns in construction of groundwater projects in Ghana”, Journal of Construction Research, No. 2, pp. 175-187.

Gidado, K. and Niazai, Gh. (2012), Causes of Project Delay In the Construction Industry in Afghanistan, University of Brighton.

Koushki, P.A., Al-Rashid, K. and Kartam, N. (2005), “Delays and cost increases in the construction of private residential projects in Kuwait”, Construction Management and Economics, Vol. 23 No. 3, pp. 285-294.

Long, L.H., Lee, Y.D. and Lee, J.Y. (2008), “Delay and cost overruns in Vietnam large construction projects: a comparison with other selected countries”, Journal of Civil Engineering, Vol. 12 No. 6, pp. 367-377.

Parchamijalal, M., Golabchi, M. and Yusefi, E. (2015), “Analysing windows- based Delay analysis methods in easy plan program and offering a framework in selecting the best Delay analysis method”, Sharif Journal Civil Engineering, Vol. 31 No. 3, pp. 41-49.

Parchamijalal, M., Shahsavand, P. and Marefat, A. (2015), “Examination and Classification of the causes of creating delays in construction projects in Iran and comparative analysis techniques delay with SCL protocol”, 11th International Conference of Project Management, Tehran, February.

The Society of Construction Law (SCL) (2002), Delay and Disruption Protocol, 1st ed., Society of Construction Law, Oxford, pp. 20-80.

Trauner, J.T., Manginelli, W.A., Lowe, J.S., Nagata, M.F. and Furniss, B.J. (2009), Construction Delays: Understanding them Clearly and Delay Analysis in Construction Analyzing them Correctly”, Elsevier Inc, London.

Wa’el Alaghbari, M., Razali, A., Kadir, A. and Ernawati, A. (2007), “The significant factors causing delay of building construction projects in Malaysia”, Engineering, Construction and Architectural Management, Vol. 14 No. 2, pp. 192-206.

Corresponding author

Parvaneh Shahsavand can be contacted at: parvaneh_shahsavand@yahoo.com