Six Sigma-Based Approach to Improve Performance in Construction Operations

Many researchers and project managers have attempted to improve project performance by applying new philosophies such as lean principle, just-in-time, pull scheduling, and last planner. However, very little research has been conducted on setting definite quantitative goals for performance improvement while considering the defect rate involved in the construction operations. This research explores practical solutions for construction performance improvement by applying the six sigma principle. This principle provides the metrics required to establish performance improvement goals and a methodology for measuring and evaluating improvement. The proposed approach is expected to achieve more reliable workflows by reducing process variability to fit in a desirable range—thereby improving the overall performance through the evaluation of the quality level in current construction operations. To verify the suggested methodology, two case studies have been presented and process simulation analyses are performed to observe the performance changes based on the six sigma principle. Critical total quality control, as the sigma level rises, is also discussed.     

Quality and Change Management Model for Large Scale Concurrent Design and Construction Projects

Concurrent design and construction has been lauded for streamlining projects in terms of time. However, such an approach may actually make projects more uncertain and complex than the traditional sequential design and construction process. The main sources of risk that have been identified with concurrent design and construction are iterative cycles that result from unanticipated errors and changes and their subsequent impacts on project performance. As an effort to address these detrimental impacts, a framework for quality and change management that identifies those negative iterative cycles is proposed. The proposed framework is incorporated into the system dynamics model of dynamic planning and control methodology (DPM), which has been developed to evaluate negative impacts of errors and changes on construction performance. Relevant to practitioners and researchers, the potential of DPM as a robust design and construction planning methodology that could effectively deal with errors and changes inherent in the design and construction process is demonstrated through a case study involving the Treble Cove road bridge in Massachusetts.     

Measuring and Improving Rationale Clarity in a University Office Building Design Process

This paper measures and improves the clarity of design rationale on an architecture, engineering, and construction (AEC) project and observes the effects. The rationale clarity framework (RCF) defines decisions in terms of components of rationale—managers, stakeholders, designers, gatekeepers, objectives (constraints and goals), alternatives, and analyses (impacts and assessment of stakeholder value). RCF defines relations and conditions of clarity for each component—coherent, concrete, connected, consistent, credible, certain, and correct. Using RCF, the rationale clarity of decisions was observed and documented on an industry case project. A decision-assistance methodology that seeks to clarify rationale, called MACDADI, was then implemented and costs and benefits from each team member’s perspective were observed. Future work is identified that can lower costs and increase benefits of clarifying rationale.     

Hybrid Model Incorporating Real Options with Process Centric and System Dynamics Modeling to Assess Value of Investments in Alternative Dispute Resolution Techniques

Project-specific dispute resolution ladders (DRLs) are typically implemented in construction projects to resolve issues arising between the project participants. The DRL typically consists of single or multiple alternative dispute resolution (ADR) techniques to address construction issues at the three levels of escalation: conflicts; disputes; and claims. However, a DRL requires significant investments to cover the direct costs incurred in-house by the project participants or, externally, if construction specialists and lawyers are recruited to assist in the resolution. Thus, the benefits of the DRL implementation in a construction project must outweigh its costs for the implementation to be worthwhile. This paper presents a methodology to study the effect of different resolution strategies on the value of the investment in a DRL using option/real option theories from financial engineering, process centric modeling, and system dynamics methodology. Of particular interest in this paper is the integration of these research methodologies into a computer model to support the evaluation of the DRL investment in a particular construction project by taking into account the characteristics of (1) the project and (2) the different ADR techniques chosen for the DRL implementation. Finally, an example is presented to illustrate the application of the computer model in a real construction project. The results of the simulation serve two main purposes. First, the results of the simulation are used to verify the intended model behavior in terms of proper integration of the three methodologies (i.e., real options, process centric, and system dynamics) in one computer system. Second, the model application to a real construction project using actual project data illustrates the potential of the model in providing the project participants with information related to the expected number of claims and change orders resolved at each level of the DRL, the change in the expected savings during the construction phase, and finally the value of the investment from the perspective of the project owner.     

Value Engineering and Optimal Building Projects

The goal of any engineering design is to obtain an optimal solution to the design problem. This paper examines how value engineering contributes to the process of obtaining an optimal solution to the design problem for a building project. The factors that determine a building project and its costs are listed and these factors fall into two groups; one group relates to specific engineering systems, while the other group is general in character and relates to the whole building. Value engineering is effective because its procedures give opportunities for raising design issues associated with the latter group of factors as well as for providing for peer-review of the design. A summary of other methods of optimal design—such as design for manufacture and assembly (DFMA), concurrent engineering, and total quality management—is given, and these methods are compared with value engineering. Cost minimization in building construction is discussed with examples from the writer's experience on building projects in West Africa and the Middle East.     

Contractor Process Improvement for Enhancing Construction Productivity

This paper presents a regression model that relates job site productivity to process improvement initiatives (PIIs) executed both before and during construction. Applied during early project stages, this model helps industry practitioners to predict the expected value of labor productivity based on certain inputs related to preconstruction planning and construction execution. The model demonstrates the strong relationship of project performance to a variety of PIIs including design completeness, definition of a project vision statement, testing oversight, and project manager experience and dedication. The correlational research methodology targeted 75 projects representing approximately $274.53 million in civil construction. The data collection effort considered 45 PIIs (independent variables) using quantitative and qualitative measures. The modeling technique involved the use of multiple linear regression, a method that exploits available data from multiple, independent sources to focus on specific outcomes. The model was developed directly from contractor specific information and subjected to rigorous statistical analysis. The model provides project managers as front line industry practitioners with a deliberate yet practical approach to project management and productivity enhancement. The modeling results include verification analysis and a discussion of the model’s usefulness and limitations.     

Using Digital Socialization to Support Geographically Dispersed AEC Project Teams

In the field of knowledge management research, socialization means to convert individual into group tacit knowledge. This process matters from the outset of an architecture, engineering, and construction (AEC) project to enhance collaborative work. Face-to-face meetings and phone calls undoubtedly facilitate socialization. However, meetings can be hard to timetable and expensive when AEC teams are geographically dispersed, whereas phone calls are cheap but offer limited capabilities for problem solving. Further, both media are not good at supporting asynchronous socialization. This study investigates the extent Internet-based media can promote cross-firm socialization and enhance collaborative work. The cross fertilization of findings from an exploratory case study with theory in computer-supported collaborative work (CSCW) informs the development of a conceptual framework on digital socialization. This framework underpins IDRAK—a proof-of-concept of a rich Internet application prototype to promote socialization in AEC projects. Our main contribution is the design of a novel methodology to evaluate the usability of digital systems to support socialization at the early design stage of an AEC project. The results from our lab experiments suggest that IDRAK can satisfactorily and efficiently enhance collaborative work. However, more research is needed, first, to evaluate the effectiveness of IDRAK to improve design quality and asynchronous socialization; and second, to investigate how other CSCW features can improve the performance of IDRAK-like systems.     

Critical Path Scheduling under Resource Calendar Constraints

Resource calendars specify nonworking days of driving resources involved in construction projects. As part of the resource availability constraints in critical path method (CPM) scheduling, resource calendars may postpone activity start time, extend activity duration, and hence prolong the total project duration. Ultimately, resource calendars bring about changes to the critical path identification. Research has yet to address how to incorporate the effects of multiple resource calendars on the total float determination. In this research, the popular P3 software is used as a tool for investigating the current practice of CPM scheduling under resource limit and calendar constraints. We assess P3’s advanced resource scheduling functions (including resource leveling and resource calendars) and identify P3’s potential errors in total float determination. Further, we propose a new method based on the forward pass analysis alone for accurately evaluating activity total float subject to resource calendar constraints. The application of the new method is illustrated with an activity-on-node case and a precedence-diagram-method case, with the results compared against those produced from P3. Our research has elucidated on some critical issues of resource-constrained scheduling in the application domain of construction project management. The findings will provide useful input for the vendors and users of the CPM software—which is not limited to P3—to improve the scheduling methodology as well as the accuracy of the resulting project schedules.     

Decision Making in Flexible Mine Production System Design Using Real Options

Large multifaceted capital projects, such as those in the mineral resource industry, are often associated with diverse sources of both internal and external risks and uncertainties. Risks can cause delays to the planned schedule of a project, add a significant cost, and greatly influence its profitability. Uncertainties can be associated with project risks, as well as with opportunities that can develop throughout the project’s lifecycle. Having the ability to plan for these uncertainties, by incorporating flexible alternatives into the system design, is increasingly recognized as critical to long-term corporate success. This paper advances the knowledge needed to incorporate flexibility in systems engineering and management for both practitioners and researchers. Flexibility is defined in this paper as the ability of a system to sustain performance, preserve a particular cost structure, adapt to internal or external changes in operating conditions, or take advantage of new opportunities that develop during a mine’s life cycle by modifying operational parameters. By engaging in planning for flexible production systems, the effects of risk on a particular project value can be examined, project volatility can be calculated, and potential flexible mining alternatives can be evaluated. Once identified, a real options valuation provides a strategic decision-making tool for mine planners to determine the value of incorporating flexible alternatives into the mine plan. This paper demonstrates that flexibility can become an equal partner among the parameters controlling the decision-making process for underground engineering construction systems, followed by industry practitioners. It presents a methodology in mine production system design by introducing flexibility into design through the application of real options valuation techniques. Real world case studies related to flexible planning and design of construction and production systems in underground hard rock mines are presented.     

Dynamic Planning and Control Methodology for Design∕Build Fast-Track Construction Projects

A dynamic planning and control methodology is developed by integrating the applications of axiomatic design concepts, concurrent engineering concepts, the graphical evaluation and review technique (GERT), and the system dynamics modeling technique. The goal of the proposed methodology is to help create a dynamic project plan for design∕build fast-track civil engineering and architectural projects where unforeseen changes can be absorbed in the project schedule without creating major interruptions. The axiomatic design concepts are applied to formulate and evaluate various work methodologies, and to create a project plan based on the selected work methodology. The concept of concurrent engineering is adapted to develop a fast-tracking framework based on the task production rate, the upstream task reliability, and downstream task sensitivity to the upstream error. The GERT diagramming scheme is used to calculate the project duration probabilistically by incorporating the possible branches and loops in the project. The system dynamics modeling technique is applied to analyze the causality links of relevant factors in the construction system, and further identifies the important variables that determine the success of a particular overlapping strategy. Consequently, with a rigorous and systemized methodology to help project planning, potential problems can be addressed early before construction. The overall increase in productivity and efficiency as a result of a better planning process can consequently promote the competitiveness of the construction industry.     

Reliability and Stability Buffering Approach: Focusing on the Issues of Errors and Changes in Concurrent Design and Construction Projects

This paper proposes a new buffering approach, reliability and stability buffering, as a means to reduce uncertainty caused by errors and changes, in particular, when concurrent design and construction is applied to an infrastructure project. The proposed buffering provides a proactive mechanism to protect the planned performance of a project with a flexibly located and systemically sized buffer. For its implementation, the reliability and stability buffering is incorporated into a dynamic design and construction project model, which simulates the impacts of errors and changes on design and construction performance and evaluates the effectiveness of the proposed buffers. Applying this buffering approach into the infrastructure project in Massachusetts, this paper concludes that (1) the amount of hidden errors and latent changes was reduced; (2) the flexibly located and distributed buffers helped identify the predecessors’ errors and changes in concurrent design and construction; (3) the impacts of hidden errors and changes were minimized, preventing their ripple effect on the succeeding activities; and (4) the quality of the coordination process was increased. Thus it shows great potential to protect design and construction performance against uncertainty in concurrent design and construction delivery of civil infrastructure projects. Such benefit obtained from the proposed buffering should be relevant to researchers and practitioners because it provides the base for future investigation for the strategic utilization of schedule buffers in an uncertain environment as well as the guideline for their effective use in practice.     

Communication Patterns in Construction at Construction Manager Level

The procurement process of construction projects has been affected by developments in the field of Information Technology, as well as by the need to cope with growing technological challenges stemming from the integration of multiple building systems into tall and complex buildings. Furthermore, since the procurement phases are undertaken simultaneously, project complexity is increased, and increased integration among them is therefore required. These constraints have made the management of complex construction projects less of an architectural and engineering issue and more of a managerial one. In turn, this has led to an increasing use of the “construction management” concept in the procurement process. This study focused on communications in construction management procurement of building and residential projects in Israel. Communications between the construction manager and the design team were found to be vital in ensuring adherence to project objectives. Communication means were classified as “formal”—written technical information, and as “informal”—verbal communications. Construction managers in Israel still use informal communications in 50% of their interactions with their project counterparts. The study concludes that design capabilities should be one of the essential qualifications required of a construction management firm. In addition to the more traditional responsibilities, such as planning, scheduling, and coordination, the scope of the construction manager’s professional duties should emphasize the aspect of quality management.     

Collaborative Planning and Scheduling of Interrelated Design Changes

During the detailed design stage of a building project, a vast amount of mostly interrelated design information is generated and communicated among specialists from several disciplines. Changes in some design information are inevitable due to the iterative nature of the design process. In many cases, when the design of a building component is modified by one discipline, this change affects the design of many related building components that are the responsibility of several other design disciplines. Commitment and resources are needed to accommodate such design changes to maintain compatibility among all the design information. Otherwise, incompatibility errors become embedded in the design information leading to numerous problems during the construction of the project. This paper presents a computer-assisted methodology that helps design managers in planning and scheduling changes with interrelated effects on the design information.     

Design Structure Matrix Implementation on a Seismic Retrofit

A void exists in development of design theory methodology within the structural engineering community. This void hampers efforts to resolve performance deficiencies including cost over-runs, unplanned rework, and suboptimal design. In manufacturing, product design and production improvements have resulted from implementation of the design structure matrix (DSM) methodology. DSM offers a means to represent, analyze, and decompose complex systems in order to improve their performance. DSM use within the architecture engineering construction (AEC) industry has been sporadic and focused primarily in the U.K. Where applied, DSM has proven effective at helping AEC design teams streamline processes to address nonlinearity (nonsequential information flows) introduced by iteration and complexity in design. When a DSM reveals iteration and highly dependent work, group brainstorming, collocated design sessions, rapid feedback, set-based design, and collaborative design aids can be used to increase overall team effectiveness. This paper examines a case study where DSM-based planning software was used on a seismic retrofit project to drive process improvement in design management. DSM correctly identified iterative activities central to design and provided the following; (1) a common vocabulary to discuss rework in the context of a multidisciplinary design team; (2) a rational method to schedule team collocation and brainstorming efforts to maximize their benefit; and (3) a means to consider iterative activities (and associated hand-offs) in design work structuring.     

Web-Enabled System Dynamics Model for Error and Change Management on Concurrent Design and Construction Projects

Construction projects are uncertain and complex in nature often because of iterative cycles caused by errors and changes. These errors and changes impair project performance and, consequently, cause schedule and cost overruns to be prevalent. Iterative cycles are more detrimental when design and construction are concurrent and often force activities to proceed without complete information. In an effort to address this issue, this paper presents the information technology aspect of the dynamic planning and control methodology (DPM), which provides a mechanism that will analyze the impact of negative iterative cycles on construction performance. In order to guarantee a smooth application of this method to real-world projects, DPM has been developed by integrating several existing methods around a core system dynamic model for quality and change management and then implementing these methods into a web-based collaborative environment. A case project, applying the developed web-based DPM, shows great potential in facilitating on-site decision making by virtue of its support of data analysis as well as real-time information sharing.     

New Project Procurement Process

In the United Kingdom, partnering was proposed by Sir Michael Latham as a means of achieving 30% cost savings in a suitable organizational climate. How this is achieved within the construction industry involves not only a mutuality of purpose between project personnel, but appropriately applied methods of process. This paper addresses the issues surrounding the way forward in partnering. By applying systematic processes to selecting partners on a short-term construction project, a case study demonstrates that cooperative working can be developed and conflict can be avoided. A unique and rigorous selection methodology known as the project delivery process was adopted for the Forton Lake Opening Bridge Millennium project in the United Kingdom, and demonstrates how significant improvements may be achieved in line with worldwide improvement targets.     

Facility Management Value-Adding Functional Analysis Model

Project management functions in facility management groups include design, construction, and renovation of facilities. The organizational structure and processes of such project management group affect the cost, quality, and duration of any project. The group's functions directly add to the overhead of the parent organization and therefore only value-adding functions are needed. The focus of this paper is to describe a value-adding functional analysis model and its application to develop a strategic direction for a parent organization. The paper presents the foundation for the analysis model, describes its application process to define and support the value-adding functions, and concludes with recommendations for organizational improvement strategy. The paper shows that value-adding functions are usually related to working closely with customer needs while considering the parent organization's requirements in project planning and control. In addition, it was found that any form of closed-market reliance on the internal resources in design and construction constrained the various processes and induced a high level of process uncertainty, which reflected negatively on project delivery time and cost.     

Programmatic Cost Risk Analysis for Highway Megaprojects

Highway megaprojects (construction projects over $100 million) are fraught with uncertainty. These projects have historically experienced increases in project costs from the time that a project is first proposed or programmed until the time that they are completed. Persistent cost underestimation reflects poorly on the industry in general but more specifically on engineers. Traditional methods take a deterministic, conservative approach to project cost estimating and then add a contingency factor that varies depending on the stage of project definition, experience, and other factors. This approach falls short, and no industry standard stochastic estimating practice is currently available. This paper presents a methodology developed by the Washington State Department of Transportation (WSDOT) for its Cost Estimating Validation Process. Nine case studies, with a mean cumulative value of over $22 billion, are presented and analyzed. Programmatic risks are summarized as economic, environmental, third party, right-of-way, program management, geotechnical, design process, construction, and other minor risks. WSDOT is successfully using the range cost output from this procedure to convey project costs to management and the public.     

八钢新建棒材高线生产线的工艺特点

介绍了八钢为实现合理产品分工,改造老系统,新建起点较高的全国产化的棒材高线生产线的设计布局、工艺流程、主要车间工艺参数、主要工艺和设备特点。新线建设为自行设计,投资低、工期短,且根据生产实践应用新技术对棒材生产线进行了优化设计,产能水平大幅提高,可为类似工程建设提供参考。