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The purpose of this research is to rank the most significant factors of organizational structure that can reduce time and cost overruns (nonphysical waste) in road projects of the developing countries. Additionally, the effect of factors of organizational structure on nonphysical waste in road projects is also measured.

Factors of organizational structure causing time and cost overrun are extracted through a content analysis of the published literature. Moreover, a questionnaire survey is carried out involving 128 professionals to assess the effect of organizational structure factors on time and cost overrun. Finally, to obtain a more objective evaluation, relative importance index and regression analysis techniques are utilized, and the most severe factors influencing time and cost overrun are indicated.

This study found out that top management support and procurement procedures are the most significant factors influencing time and cost overruns in road projects of the developing countries.

A small number of studies have been conducted to investigate the effect of factors of organizational structure on time and cost overrun in the construction industry. And even more, its relation with respect to road projects of the developing countries is limited. This research highlights the effect of most significant factors of organizational structure that influence the nonphysical waste in road projects of the developing countries. Therefore, this study adds to the body of knowledge by recommending that all the stakeholders of construction project should pay close attention toward these factors to control the enigma of time and cost overrun. It might also prove helpful, if implemented to its full extent, in all the road construction activities undertaken.

In Ghana, the duration of construction projects from inception to completion is becoming a great concern, recently, especially among clients and beneficiaries, because of the rising interest rates, inflation, development plan targets, among other factors. Hence the need to understand the causes of delays and cost overrun in the construction sector has become more important than ever. This study therefore aims to identify the major factors underlying time and cost overruns in projects related to the education sector in Ghana to proffer practical solutions in addressing them.

The study conducted a survey among clients’ consultants and representatives of the contractors working on about 60 government school projects. A relative importance index was used to determine the relative effects of the factors causing construction time and cost overruns.

The key factors causing construction time overrun were: financial problems, unrealistic contract durations imposed by clients, poorly defined project scope, client-initiated variations, under-estimation of project cost by consultants, poor inspection/supervision of projects by consultants. Other factors were underestimation of project complexity by contractors, poor site management, inappropriate construction methods used by contractors and delays in the issuance of permits by government agencies. Factors affecting cost overruns were financial difficulty by client, delays in payments of completed works, variations in designs, lack of communications plans, poor feasibility and project analysis, poor financial management on site and material price fluctuations.

The research was limited to only the educational sector projects.

Practically, this study highlights for the construction sector the critical factors causing project time and cost overruns in Ghana. Identification of these factors provides the basis for pragmatic solutions to enhance the chances of project success.

The identification and solutions to project time and cost overruns, especially for educational sector projects, contribute toward making public goods more affordable and accessible to most citizens, particularly in developing countries.

This study contributes to the debate on factors causing project time and cost overruns in the construction sector especially from a developing country’s perspective.

The purpose of this paper is to explore the impact that cost overruns and time delays exert on large public construction projects to clarify how past and current research regard factors causing cost overruns and time delays in large public construction projects.

This paper, which is based on an analysis of a literature selection consisting of 40 journal articles, investigates and ranks the occurrence of and the explanations for cost overruns and time delays in large public construction projects. The study makes use of a kiviat diagram/radar chart in order to visualize multivariate data.

Aggregated rankings of important causes of cost overruns and time delays are reported. These show a strong emphasis on the management aspect as a primary cause of cost overruns and delays. Additionally, there seems to be a trend toward deemphasizing the role of financial considerations in explaining cost overruns and delays. It is argued that there needs to be a more rigorous assessment of the impact that each factor has on cost increases and delays based on factual observed data as opposed to retrospective accounts from questionnaire respondents.

Only public construction projects have been considered. The results will not be directly applicable to privately funded construction projects and/or projects of a smaller size.

The use of trend data, as illustrated in a kiviat diagram, showing how different ranking factors causing cost overruns and time delays has changed in importance over time.

We investigate causes for the cost overrun and delay of the railway project Stuttgart 21. Besides, we try to forecast the actual costs and completion date at an early stage.

The results of exploratory research show the causes for the cost overrun and delay of Stuttgart 21; we compare our findings with other railway projects. To estimate the costs at an early stage, the reference class forecasting (RCF) model is applied; to estimate the time, we apply an OLS regression.

We find that the following causes are relevant for the cost overrun and delay of Stuttgart 21: scope changes, geological conditions, high risk-taking propensity, extended implementation, price overshoot, conflict of interests and lack of citizens' participation. The current estimated costs are within our 95% confidence interval based on RCF; our time forecast underestimates or substantially overestimates the duration actually required.

A limitation of our approach is the low number of comparable projects which are available.

The use of hyperbolic function or stepwise exponential discount function can help to give a clearer picture of the costs and benefits. The straightforward use of the RFC for costs and OLS for time should motivate more decision-makers to estimate the actual costs and time which are necessary in the light of the rising demand for democratic participation amongst citizens.

More realistic estimates can help to reduce the significant distortion at the beginning of infrastructure projects.

We are among the first who use the RCF to estimate the costs in Germany. Furthermore, the hyperbolic discounting function is added as a further theoretical explanation for cost underestimation.

Delays and cost overruns are evidently frequent problems in the construction industries of many developed and developing countries. The purpose of this paper is to assess factors leading to time overruns (delays) and cost overruns in construction projects in the Gaza Strip. Since there appear to be additional special contributors to delays here, the relative perceptions of contractors, consultants and owners are compared, based on a listing of causal factors derived from previous studies elsewhere, together with other factors arising from special conditions in the Gaza Strip.

A survey of a randomly selected samples yielded responses from 66 contractors, 27 consultants, and 31 owners. The survey included 110 delay factors/causes which were grouped into 12 major groups. The same survey also included 42 cost overrun factors. The level of importance of the delays and cost overrun factors were measured and ranked by their importance indexes, according to the perspectives of contractors, consultants, and owners.

There seems to be a general agreement between contractors, consultants and owners regarding causes of delays and cost overruns. The main four causes of time delays included strikes and border closures, material‐related factors, lack of materials in markets, and delays in materials delivery to the site. Additionally, the main three causes for cost overruns included price fluctuations of construction materials, contractor delays in material and equipment delivery, and inflation.

The outcome of this paper will assist owners, contractors, and consultants in understanding the reasons for delays and cost overruns, thus eliminating or minimizing these causes. This could be achieved by better management of the projects and by finding new methods for storing the critical materials from the beginning of the project. Furthermore, the local government is advised to initiate legislation to overcome problems arising from monopolies in the supply of construction materials.

Variation orders are a common occurrence in construction projects and their impacts have been studied by various authors. However, the contribution of project variations to construction cost and time overruns is yet to be established. The purpose of this study is to assess the significance of variations as a cause of cost and time overruns.

Using a questionnaire survey, responses were obtained from 50 project participants on the causes and effects of project variations. Cost and time data were also collected on 30 completed building projects. The analysis used importance indices and F‐ and t‐tests. The results indicated that variations had a significant effect and accounted for about 79 and 68 per cent of the cost and time overruns, respectively, for the projects studied.

The results indicated that variations had a significant effect on project cost and time overruns and accounted for about 79 and 68 per cent of the cost and time overruns, respectively, for the projects studied. Project type and size were found to have no significant effect on the contribution of variations to cost and time overruns. The results also showed that changes in specifications and scope, initiated mostly by project owners and their consultants, were the most prevalent sources of variation.

The results of this study indicates the cost and time significance of project. This will enable project owners, consultants, contractors and other stakeholders to better understand and appreciate the real impact of variations on project performance.

This paper aims to focus on developing a baseline model for time overrun.

Information on 321 completed construction projects used to assess the predictive performance of two statistical techniques, namely, multiple regression and the Bayesian approach.

The eventual results from the Bayesian Markov chain Monte Carlo model were observed to improve the predictive ability of the model compared with multiple linear regression. Besides the unique nuances peculiar with projects executed, the scope factors initial duration, gross floor area and number of storeys have been observed to be stable predictors of time overrun.

This current model contributes to improving the reliability of predicting time overruns.

In recent years, cost overrun becomes a common problem in steel building construction projects. The average percentage can vary widely depending on the project type, size, complexity and location. The steel structure change ratio in Taiwan is from 1 to 18% in statistics. The contractors always put every possible effort into preventing or mitigating project cost overruns, and one of the approaches is an accurate cost overrun risk estimate. Traditional project cost overrun risk assessment models mainly focus on macro-level evaluation and may not function well for the project-specific level (micro-level). This study creates a network-like connection model between the outcome (i.e. cost overrun risk) and the associated root causes in which the project status evaluation checklists of design, manufacturing, construction and interfaces are used to evaluate the checklists' influences through the Bayesian network (BN) composed by intermediate causes.

Due to the constraint of data availability, BN nodes, relationships and conditional probabilities are defined to establish a BN-based steel building project cost overrun assessment model following the knowledge of experts. Because of the complexity of the BN, the construction of the BN structure is first to build BN's fault tree (FT) hierarchy. And then, basic BN framework is constructed by the transformation of the FT hierarchy. Furthermore, some worthwhile additional arcs among BN nodes are inserted if necessary. Furthermore, conditional probability tables (CPTs) among BN nodes are explored by experts following the concept of the ranked node. Finally, the BN-based model was validated against the final cost analysis reports of 15 steel building projects done in Taiwan and both were highly consistent. The overall BN-based model construction process consists of three steps: (1) FT construction and BN framework transformation, (2) CPT computation and (3) model validation.

This study established a network-like bridge model between the outcome (i.e. cost overrun risk) and the root causes in a network of which cost influences are evaluated through the project-specific status evaluation checklists of design, manufacturing, construction and interfaces. This study overcame several limitations of the previous cost overrun risk assessment models: (1) few past research support assessment of cost overrun based on real-time project-owned data and (2) the traditional causal models inadequately depict interdependencies among influence factors of cost overrun at the network. The main influence factors of the cost overrun risk at the steel building projects in Taiwan were also examined using sensitivity analysis. The main root causes of cost overrun in steel building projects are design management and interface integration.

The proposed model belongs to the project-specific causal assessment model using real-time project-owned status checklist data as input. Such a model was seldom surveyed in the past due to the complicated interdependence among causes in the network. For practical use, a convenient and simple regression equation was also developed to forecast the cost overrun risk of the steel building project based on the root causes as input. Based on the analysis of cost overrun risk and significant influence factors, proper tailor-made preventive strategies are established to reduce the occurrence of cost overrun at the project.

Schedule and cost overrun analysis for a typical research & development (R&D) project is necessary to identify and mitigate the non-feasible alternatives at the design stage. Typically, this should include an analysis of technological and economic factors of R&D project. This paper aims to discuss these issues.

This research proposes an integrated analytic network process (ANP) and reusable system dynamics (SD) model for a quick and strategically consistent decision making. The technological and economic factors of R&D project were first identified and compiled through a systematic literature review. An ANP model was first developed for calculating Risk Priority Index (RPI) for set of technological and economic factors. The computed RPI are considered as an input to SD models. Two SD models (technological and economic) are developed to undertake a detailed investigation on effect of individual factor on schedule and cost overrun. The approach is exemplified for a case of government R&D project in India.

ANP identifies “Testing & qualification facility” and “Raw material availability” as the highest RPI factors. A detailed sensitivity analysis of SD models suggests that technological factors such as “Design Changes,” “Hidden Activities,” and “Lack of Expertise” and economic factors such as “Project delays,” “Unexpected incidents” and “Conflicts” have the highest influence on schedule and cost overrun.

The outcomes of this research can help managers to estimate the severity of various technological and economic factors on cost and schedule overrun and develop an adequate risk mitigation contingency plan.

In case of R&D projects where systems are being developed for the first time, changes are inevitable, and hence schedule and cost management plays a very important role in its success. This paper proposes an integrated reusable approach of ANP and SD for analyzing the influence of technological and economic factors on schedule and cost overrun of R&D project.