Sharareh Kermanshachi

Most construction projects are subject to disagreements among the primary stakeholders (owners, engineers/designers, and contractors) which, if not addressed and resolved in a timely manner, become very time consuming and costly. Although these conflicts and disagreements have the potential to adversely affect project schedule performance and success, their undesired consequences rarely have been studied. Therefore, the aim of this study was to investigate the impact of the primary stakeholders' internal and external conflicts on engineering, procurement, and construction (EPC) schedule performance. To achieve this objective, potential conflict scenarios were initially defined. Then, data associated with 30 completed case studies of construction projects was collected and analyzed. Two-sample t-test statistical tests were utilized to assess the impact of various potential conflict scenarios on project schedule performance. Next, Cohen's d method was utilized to measure the weights associated with each of the identified scenarios. It was concluded from the results that internal conflicts among contractors and external conflicts between designers and contractors have a significant impact on schedule performance associated with the engineering, procurement, and construction phases. Additionally, the results revealed that conflicts between contractor entities seriously affect the design and procurement schedule performance. This study will assist project managers in effectively allocating resources, based on their impact on schedule performance throughout the project. The findings of this study will also provide guidance to project decision makers, helping them proactively plan how to effectively address disagreements at the early stages of their lifecycle. 1 INTRODUCTION In every construction project, primary and secondary stakeholders at different levels and with different responsibilities must communicate with each other. While effective communication works as a lubricant for the project process and expedites steps and tasks, ineffective communication acts against the normal project flow and decreases the pace of a project (Kamalirad and Kermanshachi, 2018; Nipa et al. 2019). Ineffective communication may cause misunderstandings and lead to eventual conflicts among stakeholders. Therefore, conflicts are expected to arise when at least two of the participants in a project can not agree (Kamalirad et al. 2017). Although stakeholders' conflicts can hinder the progress of civil and other engineering projects, and have a serious impact on EPC schedule performance, the phase-based impact of project conflicts on schedule performance rarely has been studied or analyzed. Therefore, the aim of this study was to investigate and analyze the conflict emergence and process in the lifetime of construction projects. The following sub-objectives were formulated to achieve these goals: (1) define all potential conflict scenarios that occur among primary stakeholders; (2) determine significant conflict scenarios that affect schedule performance; and (3) classify the conflict scenarios, based on the size of the resulting impact. Since this study analyzes and quantifies conflicts based on their impact on schedule performance, its findings can help to improve the quality of communication and project schedule performance. In other words, the outcome of this paper

In the initial steps of construction projects, contractors plan the construction processes and timetables as accurately as possible; however, a number of change orders are inevitable. It is important for owners and contractors to know which variables more critically violate the project's process and timing. In this study, a sensitivity analysis was performed to analyze the levels of impact of the variables that affect project performance and duration. The analysis was performed for a typical project plan, to understand how the plan changed with deviations in the variables. The results showed that project duration was the most sensitive variable to project schedule performance. This effect, however, was only seen after a certain reduction in the project deadline. The results of this study can be used by project planners to avoid unnecessary change orders in a construction project. 1 INTRODUCTION A systematic approach is required for exploring the response of a model to varying inputs, to achieve reliable insight into the behavior of the model (Hamby, 1994; Hicks et al., 2015). A sensitivity analysis studies the qualitative or quantitative changes in the output of a model that are due to fluctuations in the variables (Saltelli et al., 2004; Borgonovo and Plischke, 2016; Kermanshachi et al. 2017). For a valuable modeling practice, the sensitivity analysis has been extensively preferred (Zhang et al., 2012). Complexity of engineering and management models and the increasing use of models with dynamic behaviors have motivated the researchers for improving these models (Pan, 2018). Sensitivity analysis could be considered the inverse of uncertainty analysis. While uncertainty analysis is the measurement of uncertainties in the inputs of a model (Hall, 2006; Ferchichi, 2018), sensitivity analysis involves identifying the influence that input factors of a model have on variations in the outputs of the model. Accordingly, it is useful to implement a sensitivity analysis to diagnose which input variables in a model or system have greater and/or less impact on its performance. The productivity of the labor is a significant parameter for evaluating a construction project's success (Hwang et al., 2009; Kermanshachi, 2016). Several researchers assessed various features of the factors impacting the labor productivity, such as change orders. Since change orders' influence on productivity depends on several factors, it becomes very complicated to accurately evaluate their impacts on labor productivity (Saltelli et al., 2004; Habibi and Kermanshachi, 2018). Factors or variables that lead to change orders in a project are called change orders factors. The sensitivity analysis of the impact of change orders on labor productivity has been rarely studied. The goal of this paper was to determine which change orders factors most affect labor productivity, and consequently schedule performance, in a construction project. To achieve the outlined goal: (1) the change orders variables influencing labor productivity were identified; (2) a quantitative dynamic model, including the relationships among different change orders variables, was developed; and (3) a sensitivity analysis was conducted to determine the impact of each of the change orders factors on labor productivity. This study answers the following questions:

A community's goal, after a disaster, is to return to a normal level of functioning as quickly as possible. Hence, the barriers that cause delays in the post-disaster recovery phase are of high importance. Policy and legal barriers are the primary obstacles to a timely post-disaster recovery process. The objectives of this paper are to identify, categorize, and weight the socioeconomic policies and legal causes that affect the process of post-disaster recovery in the U.S. For this purpose, a thorough review was performed of more than 300 scholarly papers, then the socioeconomic policies and legal post-disaster recovery barriers (PDRBs) to timely recovery were identified and classified into either social or economic categories. Finally, the PDRBs were weighted and ranked through a survey, and some recommendations were presented for ways to prevent delays in the recovery process. Fifteen PDRBs in the social and economic categories were identified from past studies, and were weighted and ranked by subject matter experts (SMEs) in post-disaster recovery. This research assists in understanding how the PDRBs affect the timeliness of recovery after a disaster, and proposes ways to mitigate the delays. The results of this study will help the stakeholders and policymakers assess the policy and legal PDRBs, and achieve timely post-disaster recovery.

During the design and construction phases, many large-scale construction projects suffer from the issuance of rework orders that ultimately lead to substantial cost overruns and major schedule delays. It is estimated that more than half of the construction industry's projects encounter significant rework and subsequent cost overruns and schedule delays. Scholars and practitioners worldwide are assessing the impact of these rework and the critical causes behind them, primarily focusing on identifying the entity-based rework indicators, as it is crucial to identify the key project, human, and organizational factors that lead to the rework. This study investigated, identified, and prioritized the human, organization, and project-based indicators of rework. Numerous research documents were reviewed to identify the leading rework indicators and prioritize them, based on their frequency of occurrence in the literature. Poor design, a vague scope definition, and site location issues are the project-based indicators most frequently found in literature; ineffective coordination and communication are the organization-based rework indicators most often found in literature; and lack of knowledge, skills, and experience are the most critical and frequently referenced indicators for human-based rework. The findings of this study will help practitioners identify the causes of rework at the right time in order to allocate resources properly for mitigating the number and cost of rework.

Energy use has increased exponentially within past decades, raising global social, economic and environmental concerns that make it important to find ways to reduce its use. In developed communities, energy consumption in buildings contributes largely to the overall energy use; therefore, finding ways to more efficiently use energy in buildings would optimize energy consumption significantly. In this study, the energy performance and associated operating costs of a building were calculated and compared with those of experiments. DOE-2, a computer simulation program capable of detailed and quick energy consumption analysis of buildings, was implemented, and it was found that heat-producing energy was the major component of the energy expended in buildings. The results of this study revealed that the amount of energy used to produce heat in the case study building was greater than that of the experimental amounts, while the amount of electricity consumed was very close to that of the experimental amounts. The findings of this study identify the issues with the DOE-2 energy software, provide empirical evidence to validate the program, and give insight to designers to help them design buildings that are more energy efficient.

Scoping studies has become an increasing popular approach to define a project and prepare it for execution. It assists to make a decision on how to efficiently proceed with the project. It is widely accepted that an inefficient scoping process is one of the major causes of project failure, cost overruns, and schedule delays in infrastructure projects. Therefore, the goal of the present study is to provide an overview of the scope definition, and also timing, tools, and resources used through scoping process by different State Transportation Agencies (STAs). The major challenges that each STA faces during the stated process in infrastructure projects are also presented. To fulfill the objectives of this study, several in-depth structured interviews with Subject Matter of Experts (SMEs) who worked in six transportation agencies were conducted and analyzed. The selected STAs for interviews were Minnesota Department of Transportation (MnDOT), Utah Department of Transportation (UDOT), Washington Department of Transportation (WSDOT), Kentucky Transportation Cabinet, Michigan Department of Transportation (MDOT), and Louisiana Department of Transportation Development (DOTD). After qualitative data analysis, the results revealed that due to different scoping definitions from agency to agency, the time frame and project scoping activities also vary. The results of scoping time demonstrated that project scoping generally starts with the identification of needs, and continues with the development of design alternatives, preliminary estimation of project costs, and identification of important milestones. It was concluded that the environmental personnel, design professionals, and maintenance personnel are more involved among construction personnel. Furthermore, the lack of time and qualified personnel to address the demand for feasibility analyses is determined as the major challenge to the scoping process. The findings of this research will assist owner entities and policy makers to structure the scoping process more appropriately in infrastructure projects.