Search results

1 – 10 of 71
Content available
Book part
Publication date: 15 April 2021

David Arditi

Abstract

Details

Streaming Culture
Type: Book
ISBN: 978-1-83982-768-6

To view the access options for this content please click here
Article
Publication date: 11 February 2019

S.M. Reza Alavipour and David Arditi

Planning for increased contractor profits should start at the time the contract is signed because low profits and lack of profitability are the primary causes of…

Abstract

Purpose

Planning for increased contractor profits should start at the time the contract is signed because low profits and lack of profitability are the primary causes of contractor failure. The purpose of this paper is to propose an integrated profit maximization model (IPMM) that aims for maximum expected profit by using time-cost tradeoff analysis, adjusted start times of activities, minimized financing cost and minimized extension of work schedule beyond the contract duration. This kind of integrated approach was never researched in the past.

Design/methodology/approach

IPMM is programmed into an automated system using MATLAB 2016a. It generates an optimal work schedule that leads to maximum profit by means of time-cost tradeoff analysis considering different activity acceleration/deceleration methods and adjusting the start/finish times of activities. While doing so, IPMM minimizes the contractor’s financing cost by considering combinations of different financing alternatives such as short-term loans, long-term loans and lines of credit. IPMM also considers the impact of extending the project duration on project profit.

Findings

IPMM is tested for different project durations, for the optimality of the solutions, differing activity start/finish times and project financing alternatives. In all cases, contractors can achieve maximum profit by using IPMM.

Research limitations/implications

IPMM considers a deterministic project schedule, whereas stochastic time-cost tradeoff analysis can improve its performance. Resource allocation and resource leveling are not considered in IPMM, but can be incorporated into the model in future research. Finally, the long computational time is a challenge that needs to be overcome in future research.

Practical implications

IPMM is likely to increase profits and improve the chances of contractors to survive and grow compared to their competitors. The practical value of IPMM is that any contractor can and should use IPMM since all the data required to run IPMM is available to the contractor at the time the contract is signed. The contractor who provides information about network logic, schedule data, cost data, contractual terms, and available financing alternatives and their APRs can use an automated IPMM that adjusts activity start times and durations, minimizes financing cost, eliminates or minimizes time extensions, minimizes total cost and maximizes expected profit.

Originality/value

Unlike any prior study that looks into contractors’ profits by considering the impact of only one or two factors at a time, this study presents an IPMM that considers all major factors that affect profits, namely, time-cost tradeoff analysis, adjusted start times of activities, minimized financing cost and minimized extension of work schedule beyond the contract duration.

Details

Engineering, Construction and Architectural Management, vol. 26 no. 1
Type: Research Article
ISSN: 0969-9988

Keywords

To view the access options for this content please click here
Article
Publication date: 21 May 2020

Osman Hürol Türkakın, Ekrem Manisalı and David Arditi

In smaller projects with limited resources, schedule updates are often not performed. In these situations, traditional delay analysis methods cannot be used as they all…

Abstract

Purpose

In smaller projects with limited resources, schedule updates are often not performed. In these situations, traditional delay analysis methods cannot be used as they all require updated schedules. The objective of this study is to develop a model that performs delay analysis by using only an as-planned schedule and the expense records kept on site.

Design/methodology/approach

This study starts out by developing an approach that estimates activity duration ranges in a network schedule by using as-planned and as-built s-curves. Monte Carlo simulation is performed to generate candidate as-built schedules using these activity duration ranges. If necessary, the duration ranges are refined by a follow-up procedure that systematically relaxes the ranges and develops new as-built schedules. The candidate schedule that has the closest s-curve to the actual s-curve is considered to be the most realistic as-built schedule. Finally, the as-planned vs. as-built delay analysis method is performed to determine which activity(ies) caused project delay. This process is automated using Matlab. A test case is used to demonstrate that the proposed automated method can work well.

Findings

The automated process developed in this study has the capability to develop activity duration ranges, perform Monte Carlo simulation, generate a large number of candidate as-built schedules, build s-curves for each of the candidate schedules and identify the most realistic one that has an s-curve that is closest to the actual as-built s-curve. The test case confirmed that the proposed automated system works well as it resulted in an as-built schedule that has an s-curve that is identical to the actual as-built s-curve. To develop an as-built schedule using this method is a reasonable way to make a case in or out of a court of law.

Research limitations/implications

Practitioners specifying activity ranges to perform Monte Carlo simulation can be characterized as subjective and perhaps arbitrary. To minimize the effects of this limitation, this study proposes a method that determines duration ranges by comparing as-built and as-planned cash-flows, and then by systematically modifying the search space. Another limitation is the assumption that the precedence logic in the as-planned network remains the same throughout construction. Since updated schedules are not available in the scenario considered in this study, and since in small projects the logic relationships are fairly stable over the short project duration, the assumption of a stable logic throughout construction may be reasonable, but this issue needs to be explored further in future research.

Practical implications

Delays are common in construction projects regardless of the size of the project. The critical path method (CPM) schedules of many smaller projects, especially in developing countries, are not updated during construction. In case updated schedules are not available, the method presented in this paper represents an automated, practical and easy-to-use tool that allows parties to a contract to perform delay analysis with only an as-planned schedule and the expense logs kept on site.

Originality/value

Since an as-built schedule cannot be built without updated schedules, and since the absence of an as-built schedule precludes the use of any delay analysis method that is acceptable in courts of law, using the method presented in this paper may very well be the only solution to the problem.

Details

Engineering, Construction and Architectural Management, vol. 27 no. 10
Type: Research Article
ISSN: 0969-9988

Keywords

To view the access options for this content please click here
Article
Publication date: 20 November 2017

Atilla Damci, David Arditi and Gul Polat

The purpose of this paper is to explore the relationship between civil engineers’ demographics (e.g. age, marital status, education, work experience) and their personal…

Abstract

Purpose

The purpose of this paper is to explore the relationship between civil engineers’ demographics (e.g. age, marital status, education, work experience) and their personal values. The objective was to predict civil engineers’ personal values based on their demographics.

Design/methodology/approach

A questionnaire survey was administered to civil engineers to collect data on their demographics and their personal values. Statistical analysis was performed to verify whether a significant statistical relationship exists between civil engineers’ demographics and their personal values.

Findings

The most important and the least important personal values were identified for civil engineers. Statistical analysis indicated that civil engineers’ values do vary based on their demographics.

Research limitations/implications

The results of this study cannot be generalized, because individuals’ personal values and demographics are, by definition, local. Location and culture may affect the personal values of civil engineers.

Practical implications

Team leaders normally have access to information about the demographics of the engineers they employ; based on the results of this study, they should be able to predict their personal values, and to make more informed decisions when appointing them to particular positions on project teams.

Originality/value

The research presented in this paper, establishes for the first time, that a linkage exists between civil engineers’ personal values and their demographics, and makes it easier for team leaders to make assignment decisions.

Details

Engineering, Construction and Architectural Management, vol. 24 no. 6
Type: Research Article
ISSN: 0969-9988

Keywords

To view the access options for this content please click here
Article
Publication date: 20 November 2017

Nathália de Paula, David Arditi and Silvio Melhado

The purpose of this paper is to investigate sustainability efforts in the managerial processes of design, consulting, construction, and facility management firms and to…

Downloads
1666

Abstract

Purpose

The purpose of this paper is to investigate sustainability efforts in the managerial processes of design, consulting, construction, and facility management firms and to identify the differences between these parties.

Design/methodology/approach

A questionnaire survey was administered to design, consulting, construction, and facility management firms in the USA to seek information about the state of sustainability efforts in these firms relative to strategic planning, marketing, business management, financial management, organizational structure, and people management. χ2 tests were performed on the data collected to determine if statistically significant differences exist between the project participants relative to sustainability efforts.

Findings

Sustainability efforts are related to a firm’s strategic positioning, reputation and experience, and hiring/employment policies, while profit margins are not higher in sustainable projects compared to traditional projects. Statistically significant differences were detected in three of the six items investigated, indicating conflicting interests among the parties.

Research limitations/implications

The study’s limitation is that it is limited to sustainability efforts in the USA.

Practical implications

It is concluded that sustainability demands have changed the nature of design, construction, and operation of buildings in ways that deserve special attention on the part of all parties involved.

Originality/value

The firms that participate in building construction projects need to adopt management practices that accommodate sustainable building design, construction, and operation in order to remain competitive in a market where demand for environmental sustainability has grown significantly in recent years.

Details

Engineering, Construction and Architectural Management, vol. 24 no. 6
Type: Research Article
ISSN: 0969-9988

Keywords

To view the access options for this content please click here
Article
Publication date: 1 June 2003

Jorge Abeid and David Arditi

A scheduling and progress control system called Photo‐net is introduced where a digital movie of construction activities can be played back along with an animation of…

Abstract

A scheduling and progress control system called Photo‐net is introduced where a digital movie of construction activities can be played back along with an animation of as‐built vs. as‐planned performance of these activities. A technique to make time‐lapse digital films of construction activities is used. A method to store a digital film is developed allowing thousands of pictures to be stored and managed in a Windows environment. A program is developed that generates critical path method (CPM) derived bar‐charts. A recording system is devised enabling the user to specify the day‐by‐day progress achieved in construction activities, allowing the program to link the playback film with the progress observed on the construction site. A set of input screens are generated by the system that provide a friendly, intuitive and easy way to enter project data. A case study is presented where the system is used, the performance of the system is discussed and the results are analyzed.

Details

Engineering, Construction and Architectural Management, vol. 10 no. 3
Type: Research Article
ISSN: 0969-9988

Keywords

Content available
Book part
Publication date: 15 April 2021

David Arditi

Abstract

Details

Streaming Culture
Type: Book
ISBN: 978-1-83982-768-6

To view the access options for this content please click here

Abstract

Details

Streaming Culture
Type: Book
ISBN: 978-1-83982-768-6

To view the access options for this content please click here
Article
Publication date: 1 February 2001

DAVID ARDITI, ONUR B. TOKDEMIR and KANGSUK SUH

Although line‐of‐balance (LOB) scheduling can be superior to bar charts and networks in repetitive‐unit construction, there are indications that its use is not widespread…

Abstract

Although line‐of‐balance (LOB) scheduling can be superior to bar charts and networks in repetitive‐unit construction, there are indications that its use is not widespread. In this study, the major limitations of the existing LOB methodology are identified and then eliminated by developing a computer program called repetitive unit scheduling system (RUSS). An effective algorithm that facilitates the implementation of LOB scheduling is developed. A tool that handles logical and strategic limitations caused by the particular characteristics of repetitive activities is provided. A learning model is developed and incorporated into LOB calculations. The program is designed to optimize resource allocation by using multiples of the natural rhythm of activities. An optimum crew size that guarantees maximum productivity in an activity is used throughout the LOB calculations to achieve cost‐optimized schedules. Non‐linear and discrete activities are incorporated into the LOB calculations. RUSS displays the LOB diagram of every individual path in the unit network. It is believed that a system such as RUSS will make the LOB method more appealing to contractors of repetitive projects.

Details

Engineering, Construction and Architectural Management, vol. 8 no. 2
Type: Research Article
ISSN: 0969-9988

Keywords

To view the access options for this content please click here
Book part
Publication date: 15 April 2021

David Arditi

Abstract

Details

Streaming Culture
Type: Book
ISBN: 978-1-83982-768-6

1 – 10 of 71