Using Computer Simulations to Plan Construction Projects Accurately

Background The construction industry has an important role in the economy of countries, as the construction industry represents 6.1 percent of the gross domestic product in the Kingdom of Saudi Arabia. A global disaster such as an epidemic causes long-term damage to society, the economy, and related industries. The recent COVID-19 epidemic is one of such disasters. The construction industry was greatly affected by the epidemic globally, as well as in the Kingdom of Saudi Arabia. Methods This research aims to determine the impact of the epidemic on construction projects and shed light on the actions taken to mitigate the impact of the epidemic through a multiple case study of three construction projects in the Kingdom of Saudi Arabia, where a questionnaire and a semi-structured interview were conducted with professionals in these projects. Descriptive analysis and the Relative Importance Index (RII) were used. Results The impact was of high importance on the project time throughout all projects, especially on the project schedule; the RII value was the maximum. Secondly for material delivery within time ranged from 0.8 – 0.91 for RII value and in terms of the mitigation actions taken, communication between project management and employees witnessed maximum effectiveness reached to 83% of participants reported a very effective response, with the help of modern technologies. Most factors ranged from limited effectiveness to ineffective. Conclusion This research contributes to determine the effects of the epidemic and the actions taken to mitigate it, which benefits the organizations and stakeholders in the field of construction and engineering project management, to develop and improve actions, and to prepare and plan for similar circumstances in the future.

The study of surface fatigue in sliding wear

The construction industry has a dynamic and complex environment. The successful completion of a construction project depends on various factors. Accordingly, construction delay is observed to happen in construction projects. It is highly affecting the construction sector and the economy of the country too. Although previous research studies identified the causes, effects, and mitigation methods separately, this study adopts a linked approach and directs to identify the effective applicable mitigation methods and their practices on each significant cause of delay in construction projects. Moreover, contractors are noted as one of the main sources of construction delay from the previous studies. Hence, this research aims to develop a framework to determine the applicable mitigation strategies and the practices of each mitigation strategy for each significant cause of contractor’s delays in construction projects in Sri Lanka. A mixed research approach was adopted to generate the research process. A literature review was conducted on construction delays, organizational and project management factors, and professional competency, mitigation strategies in delay management. The significant causes of delays and effective mitigation strategies were ranked through a questionnaire survey using a Likert scale. Project Managers and Quantity Surveyors in the Sri Lankan construction industry were selected in the ratio of 1:3 respectively for the interview as they are mostly engaged with delay management. Also, the respondents were limited to 68 and the collected data were analysed through the Relative Important Index (RII) method, to rank the significant causes and mitigation strategies. Then techniques and possible mitigation strategies were found through interviews and content analysis was used to analyse the data. The findings indicated that most of the contractor’s delays can be mitigated through applying proper mitigation strategies as effective management approaches in the construction projects such as effective project planning and schedules of construction works, maintain positive financial stability and well qualified and experienced professionals and staff, effective strategic planning, risk analysis, and management, selection of suitable sub-contractor and management and effective site management and supervision. In addition to that, inaccurate planning and scheduling of the project, financial dishonesty, poor procurement of construction materials, ineffective time management of contractors, and incompetence of management professionals and staffs were identified as the most significant contractor’s causes of delays in construction management.
 Keywords: Delays, Significant Causes, Mitigation, Construction Management, Construction Projects.

Integrated carbon emission estimation method for construction operation and project scheduling

An extensive application of project network analysis in construction project management has been observed in the last few decades. The scheduling of construction projects is generally carried out using the conventional project scheduling methodologies such as Critical Path Method (CPM), Precedence Diagramming Method (PDM), Programme Evaluation and Review Technique (PERT), and so on. However, construction processes are highly repetitive in functionality. This characteristic makes construction projects more robust and stochastic, and thus requires a neoteric scheduling method rather than the conventional project scheduling techniques thereof. Consequently, an intriguing stochastic project network technique known as Graphical Evaluation and Review Technique (GERT), which is generally used in the industrial scheduling, is proposed to overcome the shortcomings of conventional construction scheduling. The nature of GERT includes probabilistic branching, feedback looping, multiple sink nodes, and multiple node realizations which cannot be achieved in the conventional construction scheduling methodologies. These remarkable features permit the construction personnel to model and analyse projects and systems of a very repetitive nature and high complexities. GERT is the solution with paragon to many real-life projects that face problems like probabilistic occurrences of events, false-starts, activity repetition and multiple outcomes. This research tries to provide a comprehensive implication of GERT for a real-time construction project.KeywordsStochastic project networkCPMPERTConstruction schedulingGERT

Bi-objective Optimization for Resource-constrained Robust Construction Project Scheduling

Construction projects are data-rich environments. However, those data are usually captured for site-specific reasons, e.g., the filing and approval of inspection requests, with little regard to how they can be leveraged for improved project management. Typically, scheduling techniques rely on general probability estimates, which do not capture the details of the site processes causing schedule deviations. This paper illustrates how machine learning techniques can mine project data to forecast delay in the midst of the project. The proposed method uses concrete pouring requests as an example of a site data stream and implements a random forest predictive model to forecast the likelihood of acceptance for these requests. Embedded in the proposed approach is an analysis that allows for the addition of probabilistic time delays associated with the forecast of rejected requests. The methodology was tested on a real-world case study, allowing for the comparison between a project duration estimate based on critical path method (CPM) with static buffers and a project duration obtained using the proposed method. The results show a difference of 10% between the two durations. The paper shows how using data streams from a construction site with machine learning techniques can enhance project duration estimates in execution.

Residential construction projects can have many risks and uncertainties that can affect their completion time. To ensure a residential construction project is completed on time, accurate duration estimates are required for each activity. The deterministic duration Critical Path Method (CPM) is extensively used in construction project scheduling. However, this method may not always yield a realistic schedule as it uses only one duration estimation for each activity. As an alternative, this study uses the Program Evaluation and Review Technique (PERT) which utilizes three duration estimates, and the Monte Carlo Simulation (MCS) which simulates the duration 5000 times. A house construction project with 24 activities was analyzed using CPM which yielded 63 days completion time. The project was then analyzed using PERT and MCS. PERT and MCS calculations found that to complete the project with a 95% level of confidence the project needed 70 and 79 days, respectively. The findings of this study indicate that PERT and MCS can assist project managers in creating a more realistic project schedule by considering the risks and uncertainties inherent in a construction project.

Characterization of true stress-true strain curves obtained by hot deformation of different types of steels

Timeliness of implementation is one of the variables in the implementation of construction projects. Evaluation and acceleration of delays projects will generally affect the use of project resources. Project delays can be overcome by making efforts, among others, with the Crashing Method which will affect various alternative costs resulting from Crashing. This study aims to understand that the delay in the construction project schedule will have an impact on the new schedule and the impact of costs that occur due to the acceleration carried out so that the project life is in accordance with the plan. Furthermore, it was analyzed for the need for additional workforce groups or only to maintain the addition of overtime. This research was conducted with descriptive analytic method, which is a research that will explain the conditions in the field in detail about project schedule delays by analyzing the magnitude of escalation of labor costs due to the acceleration of the duration of each activity so that the project schedule returns to the plan age.

The purpose of the research is to look after establishing an appropriate solution for the problems in Iraqi construction projects which have been affected in the last years. It aims to evaluate the problems and then fix and/or at least mitigate them properly. It takes a construction project in the petroleum industry as a case study so that it can identify the realistic causes of project problems. In regard to research methodology, this research remarks on the root causes of project delay in the previous studies in Iraq, Oman and Qatar that is realised as a secondary data. Also, primary data is conducted to collect up to date information by using questionnaire. It exposes the main problems in Iraqi construction projects which are project delay, change in design, plan, scope and specifications and project cost overrun. The root cause of project delay is to accept the lowest bidding prices from the contractors and financial difficulty from the contractors. To improve the project management implementation that may require applying one of the project management methodologies in Iraqi construction projects. This research recommends applying PMBoK because it could deal with the project schedule which is the important thing recently and with cost, quality, communication and stakeholder.

Construction projects are constrained by time, cost, and quality, thus requiring effective control methods to ensure successful implementation. This study aims to compare the Critical Path Method and the Precedence Diagram Method in controlling project duration and costs on the Rehabilitation Project of TK Kartika IX-15 Teachers’ Room, which had a normal duration of 45 days. The research employed a quantitative approach using secondary data such as the project time schedule, budget plan, and progress reports. The analysis involved developing project networks using Critical Path Method and Precedemce Diagram Method, calculating forward pass, backward pass, total float, and conducting acceleration simulations through the addition of overtime work. The findings indicate that Critical Path Method shortens the project duration to 37 days, resulting in an 8-day acceleration with a cost slope of Rp1,058,867.59. Meanwhile, Precedence Diagram Method produces a shorter duration of 29 days, equivalent to a 16-day acceleration, with a lower cost slope of Rp928,354.77. These results demonstrate that Precedence Diagram Method offers better flexibility in managing activity relationships, enabling more efficient cost savings and schedule compression. Therefore, Precedence Diagram Method is considered more effective than Critical Parh Method in optimizing both time and cost control for this project. Keywords : Construction Project, Critical Path Method, Precedence Diagram Method, Project Scheduling, Cost Slope

The study investigated the effects of ineffective scheduling on the completion of construction projects; identified causes of poor planning and ineffective scheduling of construction projects by industry experts; and provided possible research solutions and industry experts recommendations to solve ineffective scheduling. Using a combination of online surveys, physical questionnaires, and statistical analysis, including the Relative Importance Index (RII), the Reliability Test, and the Statistical Package for the Social Sciences (SPSS). The analysis of factors influencing construction project scheduling reveals a hierarchy of challenges, with "Time Overrun" and "Cost Overrun" emerging as the most significant concerns, obtaining RII values of 0.8892 and 0.8246, respectively. The "Compromise of Project Quality," ranked third with an RII value of 0.8077, highlights the adverse effects of ineffective scheduling, where time constraints and rushed work undermine the quality of construction projects, potentially resulting in costly rework and repairs. Moreover, the research identified the top three recurring causes of ineffective scheduling, including "Poor Decision-Making Regarding Activity Criticality," "Lack of Finance for Project Execution," and "Lack of Expertise in Scheduling." Addressing these core issues is essential for stakeholders seeking to enhance scheduling efficiency and reduce delays. Additional influential elements, such as "Inaccurate Estimate of Materials Requirement," "Insufficient Project Details Available," and "Inadequate Knowledge of Project/Work Activities," also warrant attention in scheduling improvement strategies. These insights illuminate the critical areas requiring attention to enhance project scheduling practices and strengthen the construction industry's reputation. In conclusion, this research provides a comprehensive roadmap for stakeholders, offering practical steps to enhance construction efficiency and mitigate project delays through improved scheduling practices.

Construction projects usually suffer from the risk of delayed completion. Consequently, delay analysis is used to evaluate and apportion the effects of delays on the project schedule, and thus liabilities can be assigned. This article introduces available delay analysis methods along with their capabilities and limitations. Also, the article provides a guide for selecting the appropriate delay analysis method. Yet, analysis of schedule delay events may be influenced by some debatable issues, including float ownership, concurrency, pacing delays, and acceleration. This article represents these issues, which reveal that there exists a gap in handling such analysis. Hence, a questionnaire is designed that intends to raise the awareness of practitioners and propose the idea of standardizing the project decisions when facing such issues. After collecting the responses from 394 participants, the results reveal that the contractor should reject to accelerate the work progress until gaining compensation entitlement as a result of employer-caused delays, taking the risk of falling into the misery of liquidated damages. Also, the results illustrate the contractor's entitlements and project decisions when facing such debatable concerns. Different from previous papers, the findings of this article propose a standard way of thinking toward these debatable issues.

Bridge construction progress monitoring using lidar and 4D design models