Uncertainty In Construction Projects Research Articles

Assessing of sustainable construction quality in Iraq under conditions of risk factors

The area generally and Iraq specifically suffers in the current period from a lot of political and economic conditions which leads to the emergence of many risk factors and uncertainty in construction projects. In addition to the nature of the climate and the lack of organizational and technical programs and scheduled and continuous preventive maintenance programs in addition to the risks of terrorism and wars. The aim of the study is to assess the extent of the impact of various risk factors on construction facilities and roads for the purpose of increasing the ability of those facilities to confront these risks through managing them and applying selected criteria from the elements of sustainable construction. A questionnaire was prepared to identify the risk factors that may exist in building and construction projects, and after the risk groups were identified through the questionnaire form and personal interviews with the project participants, those groups were analyzed using the structural equation model in the program (PLS -SEM). The results showed that the ecological, economic, political, technical and social risk factors have a clear impact on the quality of sustainable construction of infrastructure projects in Iraq, and thus a clear influence on the project objectives (cost, duration and quality).

Resilient Scheduling as a Response to Uncertainty in Construction Projects

Complex construction projects are developed in a dynamic environment, where uncertainty conditions have a great potential to affect project deliverables. In an attempt to efficiently deal with the negative impacts of uncertainty, resilient baseline schedules are produced to improve the probability of reaching project goals, such as respecting the due date and reaching the expected profit. Prior to introducing the resilient scheduling procedure, a taxonomy model was built to account for uncertainty sources in construction projects. Thence, a multi-objective optimization model is presented to manage the impact of uncertainty. This approach can be described as a complex trade-off analysis between three important features of a construction project: duration, stability, and profit. The result of the suggested procedure is presented in a form of a resilient baseline schedule, so the ability of a schedule to absorb uncertain perturbations is improved. The proposed optimization problem is illustrated on the example project network, along which the probabilistic simulation method was used to validate the results of the scheduling process in uncertain conditions. The proposed resilient scheduling approach leads to more accurate forecasting, so the project planning calculations are accepted with increased confidence levels.

Managing uncertainty in fast-track construction projects: case study from South Africa

While academic researchers have proposed various theories for managing risk and uncertainty in construction projects, most of the propositions are conceptual in nature and based on analytical modelling approaches rarely used in practice. This research was triggered by an observation in which a R1·5 billion (∼US$100 million) fast-track New Universities Project in South Africa was successfully delivered within budget despite up to 74% of the project scope not being capable of being priced by the contractor at the start of construction. The aim of this paper was to examine the client’s delivery-management approach used to manage uncertainty and deliver within budget successfully. The evidence from document analyses and interviews with the client delivery-management team members shows that setting a rigorous control budget, designing to the budget, working collaboratively, disciplined management of the control budget and continuous value engineering were the key client management techniques used to manage the high degree of uncertainty and deliver the project within budget successfully. Given that these are client-led delivery-management issues, the findings fill an important gap in the knowledge and understanding of how infrastructure project outcomes can be significantly improved on when the client functions as the leader of the infrastructure delivery process.

The General Understanding Of Risk In Construction Industry In Ghana: The Consultant Perspective.

The roll of consultants in construction industry cannot be under estimated, from project conception to final completion the consultants are front liners therefore there is a need to understand their perception on risk in construction industry for their effective functioning. The purpose of the study was to understand how consultants in Ghana perceive risk in construction industry. The study objective was to identify consultant’s perception on the causes of risk in construction industry in Ghana and examine the relationship between consultant’s concept of risk and perception on uncertainty.The study adopted a quantitative approach involving a cross-sectional design using survey, questionnaires administered to a population of 355 consultants of the Ghana Consulting Engineering Association (GCEA). Descriptive statistics, cross tabulations, Chi-square were used to analyze the resulting data. The study found that the major causes of risk in construction are usage of substandard materials in construction industry, harmful work-related experience, and the dangers in construction. The study further shown that risks were not the same as uncertainties in construction projects that risks could not lead to positive outcome but the positivity of risks depends on the type of projects the consultants worked on. It also reveal that theft and lack of a critical checklist were the major sources of risks in the construction industry. On the bases of the founding’s the study sort to recommend that effective and efficient monitory system should be implemented at construction site to curtail all issues related to theft. Again investigation should be conducted to examine consultants’ perception on the impact of risks in the construction industry.

Decisional Uncertainties in Construction Projects as a Cause of Disputes and Their Formal Legal Interpretation by the Courts: Review of Legal Cases in the United Kingdom

AbstractDisputes are an expected, common, and well-documented part of the construction industry worldwide. This is attributable to the interwoven interactions of disparate parties in construction p...

Simulating Uncertainties in Construction Projects with Chronographical Scheduling Logic

AbstractThe more complex a project, the more attractive nontraditional project delivery methods like design-build or fast-tracking become with these delivery methods and uncertainty has to be expli...

Metanetwork Framework for Integrated Performance Assessment under Uncertainty in Construction Projects

AbstractThe objective of this study is to create and test an integrated framework for assessment of vulnerability to uncertainty in complex projects. In the proposed framework, construction projects are conceptualized as metanetworks composed of different nodes (i.e., human agents, information, resources, and tasks) and links. The effects of uncertain events are translated into perturbations in the nodes and links of project metanetworks. These uncertainty-induced perturbations are reflected as transformations in a project’s topological structure, and thus negatively affect the efficiency of the project’s metanetwork. The extent of the variation in the efficiency of a project’s metanetwork is used to determine the extent of vulnerability to uncertainty. The application of the proposed framework is shown in an illustrative case study related to a tunneling project. In the case study, various scenarios related to different uncertain events were simulated through the use of dynamic network analysis and Monte...

Factors affecting stakeholder management in construction projects in the Gaza Strip

One of the major emerging concerns in the management of construction projects is the recognition and management of project stakeholders, since the stakeholders are a major source of uncertainty in construction projects. The construction industry in the Gaza Strip has involved a diverse range of stakeholders. This research aims to evaluate the most common factors affecting the stakeholder management process in construction projects. A literature review was conducted on topics related to stakeholder management. A questionnaire survey was carried out among professionals in the construction industry. Ninety-eight questionnaires were distributed to experts from government, municipality, and non-government organizations. Sixty-seven questionnaires were received, with a 68% response rate. The mean and relative importance index were used to analyse the questionnaire results. The main factors affecting the stakeholder management process are hiring a project manager with high competency, transparent evaluation of the alternative solution, ensuring effective communication between the project and its stakeholder, setting common goals and objectives for the project, and exploring the stakeholders' needs and expectations.

Integrated Prefabrication Configuration and Component Grouping for Resource Optimization of Precast Production

AbstractIt may be possible to reduce uncertainty in construction projects by adopting the prefabrication method. In this method, components are produced in factories and transported to the construction site to satisfy installation demands. For successful and effective prefabrication, the project designer and precaster must develop an integrated plan to manage the available resources in a way that satisfies design flexibility, production constraints, and installation demands. Configuring individual building elements and forming building components or modular units will result in employing a higher degree of prefabrication for higher productivity and ease of construction. The production of such complex configurations requires complex molds. To achieve optimization of resources and costs for the precast production of complex configurations, two new ideas have been adopted: namely prefabrication configuration and component groups; these are incorporated into the mixed integer linear programming (MILP) model. ...

Volume Uncertainty in Construction Projects: A Real Options Approach

The levels of uncertainty surrounding construction projects are particularly high and construction managers should be aware that adequately managing the effects of the different types of uncertainty may lead to an increase in the overall performance of construction companies. The model proposed focus on the impact that a specific type of uncertainty - volume uncertainty - may produce on the project value. Volume uncertainty is present in most construction projects since managers do not know, during the bid preparation stage, the exact volume of work that will be executed during the project's life cycle. Since volume uncertainty leads to profit uncertainty, the model integrates a discrete-time stochastic variable, designated as “additional value”, i.e., the value that does not directly derive from the execution of the tasks specified in the bid documents, and which can only be properly quantified by undertaking an incremental investment in human capital and technology. The model determines that, even only recurring to the skills of their own experienced staff, contractors will produce a more competitive bid, provided that the expected amount for the additional profit is greater than zero. However, construction managers often need to hire specialized firms and highly skilled professionals in order to quantify the expected amount of additional value and, hence, the impact of such additional value in the optimal bidding price. Based on the option to sign the contract and to perform the project by the selected bidder, identified and evaluated by Ribeiro et al. ((2013)), the model's outcome is the threshold value for this incremental investment. A decision rule is then reached: construction managers should invest in human capital and technology provided that the cost of such incremental investment does not exceed the predetermined threshold value. The model also proposes new forms of reaching the optimal bidding price, considering solely the effects of the non-incremental investment and also considering the impact of the incremental investment in human capital and technology.

Probabilistic models for tunnel construction risk assessment

The paper introduces different probabilistic models for prediction of tunnel construction risk. First, a simple probabilistic model for the estimation of the damage due to tunnel construction failures (e.g. cave-in collapses) is proposed. It can be used in conjunction with a deterministic estimate of the construction time/costs as a support for decision-making in tunnel construction projects. The occurrence of failures is modelled as an inhomogeneous Poisson process. The model takes into account the heterogeneity of the environment along the tunnel (changing geological conditions, changing damage potential) and it includes the influence of common factors such as human and organisational aspects. The damages caused by the failures are modelled as uncertain and they are thus represented by full probability distributions in the model. Second, the decision-making under uncertainty in construction projects is discussed. The use of the concept of utility for considering the attitude of the stakeholder to risk is demonstrated. The simple probabilistic model and the decision-making concept are applied to a case study of construction of a 480-m-long tunnel. Third, stochastic models for specific problems of tunnel construction, such as impacts of excavation on surface structures or probabilistic prediction of thickness of rock overburden, are introduced. The use of the models is illustrated on an example from Blanka tunnel in Prague.

A scheduling methodology for dealing with uncertainty in construction projects

PurposeThe purpose of this paper is to address the problem of scheduling under uncertainty in construction projects. The existing methods for determining a project schedule are based on assumption of complete knowledge of project parameters; but in reality there is uncertainty in construction projects, deriving from a multitude of context‐dependent sources and often provided as outcome of a risk analysis process. Thus, classical deterministic analysis might provide a schedule which is not sufficiently protected against possible disruptions.Design/methodology/approachA quantitative methodology is developed for planning construction projects under uncertainty aimed at determining a reliable resource feasible project schedule by taking into account the available probabilistic information to produce solutions that are less sensitive to perturbations that occur on line. The methodology relies on a computer‐supported system that allows to identify, analyze and quantify the schedule reliability and the impact of possible disruptions on the duration of the project.FindingsIt is found that the proposed methodology can exploit more information about the uncertain parameters than the commonly‐used deterministic method, and it provides an improved understanding of the schedule reliability in presence of uncertainty. The schedule generated with a classical deterministic method sets a completely unrealistic planned project delivery date of about 1,250 days, with a probability around 50 per cent to be exceeded. This behavior can be very unsatisfactory for construction projects for which high penalties are usually associated to heavy due date violations.Originality/valueThis paper presents an approach for robust scheduling of construction project problem under uncertainty. We provide a tool able to support managers in developing a workable and realistic project schedule to be used as a guideline for project control and monitoring.

Fuzzy Monte Carlo Simulation and Risk Assessment in Construction

Abstract: Monte Carlo simulation has been used extensively for addressing probabilistic uncertainty in range estimating for construction projects. However, subjective and linguistically expressed information results in added non‐probabilistic uncertainty in construction management. Fuzzy logic has been used successfully for representing such uncertainties in construction projects. In practice, an approach that can handle both random and fuzzy uncertainties in a risk assessment model is necessary. This article discusses the deficiencies of the available methods and proposes a Fuzzy Monte Carlo Simulation (FMCS) framework for risk analysis of construction projects. In this framework, we construct a fuzzy cumulative distribution function as a novel way to represent uncertainty. To verify the feasibility of the FMCS framework and demonstrate its main features, the authors have developed a special purpose simulation template for cost range estimating. This template is employed to estimate the cost of a highway overpass project.

Behavioral Transition: A Framework for the Construction Conflict--Tension Relationship

Conflicts are inevitable in construction projects. One of the reasons is that all construction projects involve complex human interactions. Previous studies have shown that behavioral states can respond dynamically as the magnitude of a conflict increases. This has been empirically demonstrated using a catastrophe-theory-based, three-variable system involving the level of construction conflict, the level of tension, and the amount of behavioral flexibility (Yiu and Cheung, 2006). This paper reports on a study that builds on the above-mentioned study by Yiu and Cheung, and examines the application of moderated multiple regression (MMR) to the three-variable system. It was found that not all MMR models display a significant moderating effect. Two out of six MMR models were found to be significant in their effect. These models affirm that the nature of the relationship between the degree of uncertainty and adversarial attitudes (or mistrust level) varies, depending on the behavioral flexibility of the parties. Disordinal interactions were also found, suggesting that the interaction between behavioral flexibility and the conflict-tension relationship can change radically. Critical points for the degree of uncertainty were also able to be calculated. Beyond these points, even a flexible individual may find difficulty in minimizing or resolving construction conflicts. As such, it is suggested that such radical changes could be prevented by minimizing the degree of uncertainty in construction projects.