Decisions in Construction Operations

A method for selecting the most desirable construction strategy is proposed in this paper. A decision analysis framework is developed considering the information on relative risk, along with the information on cost, benefit, and consequences of each construction strategy. Many factors affect the safety of construction operations. Labor skill, supervisors' experience and attendance, condition of falsework, weather conditions, type of equipment, level of operator's experience, etc., may be considered as the main factors that affect the safety of construction operations. From an engineering point of view, these factors are always desirable to be in their best states. However, it may not be practical in many cases due to time and money constraints. Consequently, the risk of failure and cost of construction operations, and the consequences of failure need to be estimated in order to decide about the optimum construction strategy. The decision problem is complicated since the state of the factors are generally expressed in linguistic terms. The theory of fuzzy sets is used to translate these terms into mathematical measures and to estimate the risk of failure. The proposed method is illustrated with the help of an example.     

Systematic Evaluation of Construction Equipment Alternatives: Case Study

Selecting the right equipment for the project is inherently a multifaceted cost and benefit evaluation process that is further compounded by the complexity of today’s building projects and the lack of systematic tools for the consideration of soft factors. This paper presents a detailed application example of a model based on an analytical hierarchy process (AHP) approach. This model was developed to address the difficulties experienced during the multifaceted process. The example illustrates how an AHP-based model helps address the multitude of qualitative, intangible factors, both among the factors themselves and then vis-à-vis costs, by means of a systematic and traceable process. The method enables project managers and their equipment selection teams to exercise their knowledge, intuition, and professional judgment, and at the same time to address the context and specifics of the particular projects under examination. The example should be helpful for construction practitioners dealing with similar equipment selection issues. Researchers may find interest in the implementation of a multiattribute-decision-making method for a typical construction management problem.     

Site Management of Work-in-Process Buffers to Enhance Project Performance Using the Reliable Commitment Model: Case Study

Buffers have been commonly used as a production strategy to protect construction processes from the negative impact of variability. Construction practitioners and researchers have proposed several buffering approaches for different production situations and contexts. However, these solutions have been impractical for managing buffers. To overcome this, this study proposes a new site methodology for managing work-in-process (WIP) buffer in repetitive projects, on the basis of the reliable commitment model (RCM). RCM is a decision-making tool based on lean principles, which uses statistical models to develop more reliable work plans at the operational level. RCM helps to manage WIP buffer in work plans by using site information and planning reliability indicators that result in improved project performance, such as labor productivity and process progress. A repetitive building project was used as a case study. The main finding was that labor productivity, process progress, and waiting times improved when using larger WIP buffers than those typically used among crews. This shows the potential of RCM as a practical tool to manage WIP buffer sizes and to promote the use of lean production strategies at the operational level.     

“Soft” Considerations in Equipment Selection for Building Construction Projects

This paper raises the issue of “soft” considerations in the selection of equipment for building construction projects. The paper aims at increasing the awareness: (1) to the nature, variety, and richness of soft factors; (2) to their significant role and potential impact on the outcome of decision making; and (3) to the inherent difficulty of evaluating them and integrating them within a comprehensive selection process. Existing state-of-the-art equipment selection models were analyzed and found to be inadequate in terms of both considering soft factors and providing mechanisms for their systematic evaluation. Six cases of large-size, complex construction projects were investigated to obtain an extensive list of typical soft factors. This investigation revealed that the consideration of soft factors in current practices is essentially unstructured and is not integrated within the selection process in a systematic manner. A desirable selection process is outlined that generally responds to the needs identified in the study. The proposition of a specific method for the quantitative treatment of soft factors and their tradeoff with cost factors is the subject of another paper.     

Consistency and Reliability of Construction Arbitration Decisions: Empirical Study

While construction arbitration is analyzed in a plethora of information, there is a paucity of hard data about the consistency and reliability of the construction arbitration decision. The assumption that an industry familiar adjudicator will provide a reliable and consistent decision in comparison with the expectation of the industry as a whole has not been tested. This paper presents the results of a study on the reliability and consistency of construction arbitration through the examination of a variety of arbitrators’ decisions on the same construction dispute scenario. Data was collected from attorneys, owners, owner representatives, contractors, and subcontractors. Compilation of the survey results finds little consistency in the arbitrator’s awards, but with much thoughtful care in award consideration. The results suggest that the arbitrator’s industry background does not influence the arbitrator’s award. There is also no significant award bias due to the arbitrator’s education level or years spent in construction business. The results also indicate that previous arbitration experience does not predict the award outcome. This paper concludes that construction arbitration is wholly unpredictable. However, the result will be a well-reasoned and unbiased decision.     

Entropy Application to Improve Construction Finance Decisions

In financial decision-making processes, the adopted weights of the objective functions have significant impacts on the final decision outcome. However, conventional rating and weighting methods exhibit difficulty in deriving appropriate weights for complex decision-making problems with imprecise information. Entropy is a quantitative measure of uncertainty and has been useful in exploring weights of attributes in decision making. A fuzzy and entropy-based mathematical approach is employed to solve the weighting problem of the objective functions in an overall cash-flow model. The multiproject being undertaken by a medium-size construction firm in Hong Kong was used as a real case study to demonstrate the application of entropy. Its application in multiproject cash flow situations is demonstrated. The results indicate that the overall before-tax profit was HK$ 0.11 millions lower after the introduction of appropriate weights. In addition, the best time to invest in new projects arising from positive cash flow was identified to be two working months earlier than the nonweight system.     

AHP-Based Equipment Selection Model for Construction Projects

Selection of equipment for construction projects, a key factor in the success of the project, is a complex process. Current models offered by the literature fail to provide adequate solutions for two major issues: the systematic evaluation of soft factors, and the weighting of soft benefits in comparison with costs. This paper presents a selection model based on analytic hierarchy process (AHP), a multiattribute decision analysis method, with a view to providing solutions for these two issues. The model has the capacity to handle a great number of different criteria in a way that truly reflects the complex reality, to incorporate the context and unique conditions of the project, and to allow for manifestation of user experience and subjective perception. The model was implemented in an in-house developed system that was improved and validated through testing by senior professionals. The main academic contribution of the study is in the modification of AHP to correspond with the nature of equipment selection and in its utilization as an effective means for the formalization of knowledge possessed by competent, experienced practitioners. On the practical side, the proposed model offers an efficient, convenient tool that forces the users into orderly, methodical thinking, guides them in making logical, consistent decisions, and provides a facility for all necessary computations.     

Modeling the Construction Management Process to Support Situational Simulations

Construction managers are decision makers who administer nontrivial processes. The replacement of highly experienced construction managers and other construction professionals is a laborious process for the industry. This paper introduces a conceptual framework for the construction management practice that serves as the foundation for the development of situational simulations. Situational simulations are temporally dynamic clinical exercises with the objective of exposing participants to rapidly unfolding events and the pressure of decision making. The application of situational simulations provides construction managers and other decision makers the opportunity of experiencing and responding to risky events without endangering the success of real projects, further enhancing their decision-making skills. The construction management conceptual framework includes a process, a product, and an information model. The analysis of a basic mathematical representation of the process model is the focus of this paper.     

Fuzzy Approach to Prequalifying Construction Contractors

Construction contractor prequalification (CCPQ) is a crucial decision making process to select capable potential bidders and ensure the success of construction projects. The purpose of CCPQ is to guarantee a contractor’s characteristic to meet the construction project’s requirements, which has been established worldwide as a standard practice. However, existing methods, i.e., marking method, subjective judgment method, etc., for contractor prequalification have been inadequate because it is difficult for decision makers to investigate contractor’s capabilities against inexact, vagueness, and qualitative criteria. The objective of this paper is to propose a fuzzy framework-based fuzzy number theory to solve construction contractor prequalification issues, which include decision criteria analysis, weights assessment, and decision model development. Finally, a case study for a tunnel construction project was used to demonstrate the feasibility of fuzzy approaches.     

Analysis of Factors Influencing Productivity Using Craftsmen Questionnaires: Case Study in a Chilean Construction Company

Improvement of productivity in construction has been a major industry challenge, given its high impact on project results. It has received increased attention from construction researchers promoting different enhancement actions, since analyzing factors affecting labor productivity is an instrumental part in this process. This paper focuses on identifying and understanding the productivity factors affecting projects in a Chilean construction company on the basis of questionnaires administered to both direct workers and midlevel employees. Analysis of the questionnaire results helped to determine organizational and managerial weaknesses and facilitated comparison of the findings with previous productivity studies. The results proved to be useful in developing recommendations for productivity improvements. The main findings indicate that the critical areas affecting construction productivity were related to materials, tools, rework, equipment, truck availability, and the workers’ motivational dynamics. These results are similar to those obtained in previous studies in the United States and in Chile. Salary expectations were found to be the main reason for turnover in the studied company, which was an aspect not mentioned in previous studies. Finally, additional analyses seem to show that some factors affecting productivity are common to construction projects across boundaries, therefore validating data aggregation and the possibility of learning from experiences in different locations and even separated in time of occurrence.     

Framework for Measuring the Rationale Clarity of AEC Design Decisions

Current architecture, engineering, and construction (AEC) design processes often rely on precedent to resolve complex decisions. However, changes to stakeholder concerns, design methods, and building products devalue much of this precedent knowledge. Project teams need to clearly communicate their decision rationale to develop consensus about design decisions. This study reviews a broad range of relevant theory from decision-based design, decision analysis, decision theory, linguistics, logic, organization theory, and social welfare. Rationale is defined as a set of assertions regarding distinct components (i.e., managers, stakeholders, designers, gatekeepers, goals, constraints, alternatives, and analysis) that support design decisions. Conditions of clarity (i.e., coherent, concrete, connected, consistent, credible, certain, and correct) are also defined. These definitions are used to measure the clarity of assertions, components, and the rationale as a whole. Taken together, this rationale clarity framework (RCF) provides a structured view that enables an objective evaluation of design decision methods.     

Case Study on the Evaluation of Equipment Flow at a Construction Site

The purpose of this study is to evaluate the effects of traffic flow of construction equipment. A large construction project requires large quantities of construction equipment. This volume can result in traffic congestion in the flow of construction equipment, which also lowers the overall efficiency of construction operations. In particular, this effect can be serious in the area where traffic bottlenecks are most likely. This study applies a multiagent-based simulation modeling approach to a real project. Through a case study, this study evaluates how traffic flow of construction equipment influences the efficiency of that equipment in construction operations and, moreover, the schedule of a project.     

Organizing Large Projects: How Managers Decide

Now tools will help managers design organization structures for large engineering and construction projects. An improved understanding of how managers decide in structuring project organizations is necessary to develop these tools and to assist managers in the systematic design of organizations tailored to meet project goals under unique situations. This paper reports a portion of results from research conducted to determine current practices in project organization design. The conclusion that adaptation dominates this process leads to several implications for industry professionals and researchers wishing to improve project performance. Recognizing the role of adaptation in current practices of organizational structuring will allow managers to avoid inertia and systematically design organizations. Researchers can assist by expanding variables in organization theory to better capture project situation and structure and by developing new tools to assist in systematic organization design.     

Strategic Group Analysis in the Construction Industry

The aim of strategic group analysis is to determine whether clusters of firms that have a similar strategic position exist within an industry or not. Findings of strategic group analysis may further be used to investigate the performance implications of strategic group membership. The objective of this paper is to identify the possible strategic groups that could exist within the Turkish construction industry by using a theoretical framework applicable for the construction industry and alternative statistical cluster analysis techniques. The achieved results pinpoint the existence of three clusters and significant differences between the performances of firms in each cluster. All of the firms in the strategic group that have the highest average performance utilize a quality differentiation strategy and have the necessary resources and capabilities that give them the opportunity to differentiate their services from others. Also, they use a systematic approach and have a collaborative environment for strategic decision making. Findings of strategic group analysis can be used by professionals to understand the current strategic position of a firm within the competitive environment and formulate strategies to shift to a better performing cluster.     

Construction Engineering Requirements for Integrating Laser Scanning Technology and Building Information Modeling

Laser scanning for rapid spatial data acquisition is an established technology in the architecture, engineering, and construction (AEC) sector with a wide range of applications. An understanding of the wide variation of technical requirements and considerations associated with these applications is critical to decision making about laser-scanning implementation on projects. Furthermore, significant industry transformations in the use of building information modeling present extraordinary opportunities for AEC professionals to employ the use of laser scanning in the context of holistic, collaborative workflows grounded in three-dimensional model-based design. This report analyzes the construction engineering requirements of laser scanning technology for applications across all phases of the project life cycle and proposes a multidisciplinary framework to integrate applications of laser scanning technology with the fundamentals of three-dimensional model-based design.     

Nondominated Archiving Multicolony Ant Algorithm in Time–Cost Trade-Off Optimization

Time–cost trade-off analysis is addressed as an important aspect of any construction project planning and control. Nonexistence of a unique solution makes the time–cost trade-off problems very difficult to tackle. As a combinatorial optimization problem one may apply heuristics or mathematical programming techniques to solve time–cost trade-off problems. In this paper, a new multicolony ant algorithm is developed and used to solve the time–cost multiobjective optimization problem. Pareto archiving together with innovative solution exchange strategy are introduced which are highly efficient in developing the Pareto front and set of nondominated solutions in a time–cost optimization problem. An 18-activity time–cost problem is used to evaluate the performance of the proposed algorithm. Results show that the proposed algorithm outperforms the well-known weighted method to develop the nondominated solutions in a combinatorial optimization problem. The paper is more relevant to researchers who are interested in developing new quantitative methods and/or algorithms for managing construction projects.     

Construction Engineering Process and Knowledge Requirements for Fostering Creative Design Solutions on Infrastructure Projects

Construction engineering for major infrastructure projects covers a wide range of activities to evaluate and select the techniques for assembling materials and components. Construction engineering inherently presents a very challenging opportunity for creative design, particularly on infrastructure projects. This construction engineering activity can be described as one of creating and developing workable, cost-effective, low-risk technical solutions for an array of infrastructure construction problems that must be solved from the plans and specifications stage through facility completion. The purpose of this paper is to illustrate a 10-step construction engineering process and define important knowledge requirements to foster creative design solutions using four case studies, including (1) positioning and holding a concrete bridge caisson in a 7-knot tidal current for a 4-month period; (2)?skidding a 55,000-t immersed tube tunnel element 200?m on dry land from casting site to launch site; (3)?building a major dam without the use of river diversion or on-site dewatering systems; and (4)?building underwater bridge piers without the use of conventional bottom-founded cofferdams. The creative design process was able to successfully devise a plan for solving highly technical construction challenges using a process-based approach. The key requirements of knowledge, skill, and experience necessary to perform these activities are presented to assist construction engineers in preparing for these creative opportunities.     

Integrated Simulation System for Construction Operation and Project Scheduling

Simulation modeling is important in predicting the productivity of construction operations and the performance of project schedules. It would be desirable if operation and project models are vertically integrated in practice. However, existing discrete event simulation systems do not allow integrating operation and project models. This paper introduces an integrated simulation system named “Construction Operation and Project Scheduling” (COPS). COPS analyzes the productivity of construction operations as well as the performance of a project schedule individually and jointly. It creates operation models, maintains these models in its operation model library, conducts sensitivity analysis with different resource combinations, finds the optimal resource combination that satisfies the user’s requirements relative to hourly production and hourly cost of the operation, feeds this information into a project schedule, and executes stochastic simulation-based scheduling. A case study is presented to demonstrate this integrated simulation system.     

Knowledge-Driven ANP Approach to Vendors Evaluation for Sustainable Construction

This paper presents a multicriteria decision-making approach to evaluate contractor candidates in the open competition of construction project procurement by means of a knowledge-framed analytic network process (KANP), which embeds a construction knowledge framework into a formal analytic network process procedure. An applied KANP model named KANP.BID is set up and used in an experimental case study. The paper concludes that the KANP.BID model is a viable and capable tool for selecting the most appropriate tender alternative under criteria of sustainable construction. It is expected that the proposed KANP.BID model can attract interest from both practitioners and researchers in terms of further research and development.     

Identification of Decision Drivers for the Strategy of Incorporating Utility Relocations into Highway Construction Contracts

The adjustment of utilities prior to highway construction is a particularly complex and challenging operation. One strategy that has been adopted in the last two decades is to incorporate utility adjustment work into highway construction contracts. In theory, this approach eliminates or reduces some of the complications and risks of utility adjustments. This paper aims to identify and analyze the decision drivers for selecting this strategy and help alleviate its implementation challenges. To this end, a comprehensive literature review and several interviews with experts from state departments of transportation and utility companies were conducted. Assessment surveys regarding the performance of recent projects that used the combined strategy were performed. Conclusions and recommendations for future research are presented.