Fast and Accurate Risk Evaluation for Scheduling Large-Scale Construction Projects

This paper presents the development of a novel probabilistic scheduling model that enables fast and accurate risk evaluation for large-scale construction projects. The model is designed to overcome the limitations of existing probabilistic scheduling methods, including the inaccuracy of the program evaluation and review technique (PERT) and the long computational time of the Monte Carlo simulation method. The model consists of three main modules: PERT model; fast and accurate multivariate normal integral method; and a newly developed approximation method. The new approximation method is designed to focus the risk analysis on the most significant paths in the project network by identifying and removing insignificant paths that are either highly correlated or have high probability of completion time. The performance of the new model is analyzed using an application example. The results of this analysis illustrate that the new model was able to reduce the computational time for a large-scale construction project by more than 94% while keeping the error of its probability estimates to less than 3%, compared with Monte Carlo Simulation methods.     

Strategic Positioning of Inventory to Match Demand in a Capital Projects Supply Chain

Industrial buyers of capital facilities have experienced and continue to experience pressure to reduce facility design and construction lead time. This pressure arises both internally (due to successes in manufacturing lead time reductions) and externally (due to competitive forces including narrowing product delivery windows). This paper presents a case study detailing one owner’s efforts to reduce the length and variability of delivery time for long-lead construction materials in order to improve overall project lead time. The owner adopted a long-term multiproject perspective, procuring material in advance of specific projects and holding it at a position in the supply chain selected to allow flexibility for customization. Reduction in lead time of 75% from order to delivery of the material resulted for individual projects within the owner’s capital plan. As a result, the material was available at the construction site well in advance of its need for erection. To study if holding material at alternative locations in the supply chain could provide a better match between delivery quantities and the demand for erection, the supply chain was simulated. In this case study, demand information was imprecise, allowing only the quantity of material delivered to be considered rather than matching specific items to specific locations. Nonetheless, the results demonstrate the utility of simulation in the capital projects supply chain and the value of improving demand forecasts.     

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.     

Profit Measures for Construction Projects

The basic issues related to profit measures of a construction project for the contractor are presented. Specifically, the problem of measuring gross operating profit and financing costs under fluctuating economic environments which has been heretofore inadequately treated in the literature of construction management is addressed. A framework for analyzing financing costs under different financial mechanisms, including the effects of overdraft and other borrowing arrangements, is presented. The general procedure is also applicable to the analysis of the effects of inflation and of work stoppages on profit. Finally, the cost of a project to the owner and the relationship between uncertainty and contract price from the views of both the owner and the contractor are considered.     

Capturing Knowledge in Construction Projects: Knowledge Platform for Contractors

Managing knowledge effectively is critical to the survival and advance of a company, especially in project-based industries such as construction. However, capturing knowledge in construction projects is a tedious task, as knowledge is usually experience based, tacit, and hard to pass on to others. In this study, a survey was carried out among eight leading Turkish construction contractors that are operating within the international construction market. The specific objectives of this survey are to find out how the tacit and explicit knowledge are captured, stored, shared, and used in forthcoming projects, as well as major drivers and barriers for knowledge management. Based on the survey, it was determined that most of these firms do not have a knowledge management strategy and a systematic way of capturing and storing tacit knowledge. A conceptual framework is proposed to formalize the knowledge-capturing process within construction companies. To demonstrate how the conceptual framework can be implemented in practice, a Web-based system, namely, Knowledge Platform for Contractors (KPfC) is presented. It is hypothesized that KPfC can be used to manage both tacit and explicit knowledge effectively in construction projects.     

Estimating Performance Time for Construction Projects

The prediction of performance time for construction projects is a problem of interest to both researchers and practitioners. This research seeks to gain insight into the significant factors impacting construction duration by developing a regression model. Data were collected for 856 facility projects completed between 1988 and 2004. These data were analyzed using Bromilow’s time-cost (BTC) model (1969) as well as multiple linear regression. The multiple linear regression model was found to provide the most acceptable prediction. As in the BTC model and previous research reported in the literature, a significant correlation was found to exist between cost and duration. However, several other factors were also identified that resulted in significantly lower than average construction durations. These include projects completed within certain management groupings, managed by a certain construction agent, and designed by in-house personnel.     

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.     

RISim: Resource-Interacted Simulation Modeling in Construction

Discrete-event simulation is an effective approach to analyze construction operations. However, it is usually time-consuming and knowledge demanding to develop a practical simulation model, and thus not cost-effective due to the uniqueness and relatively short life of construction projects. The capability of discrete-event simulation modeling has not been popularly recognized by site managers until recently. A clear and explicit solution is to simplify and speed up the model development cycle, so as to enable users without much knowledge of simulation technology to easily generate a model in a relatively short period of time. In this paper, a resource-interacted simulation (RISim) modeling approach is presented, which adopts a resource oriented methodology to promote an intuitive feel to simulation modeling. In RISim, an operation is modeled in two abstraction levels—namely, the resource level and process level. An operation is viewed as a collection of resources and their interactions. Complex resources and simple resources are used to respectively represent resources with or without their own processes. The operation logic is mainly represented with internal complex resource flows, which are integrated by simple resource flows between complex resources. Resource flows can be easily conceived by site managers, enabling them to build up the logic naturally and simply. A resource library is used to implement resource reusability. Finally, an example in concrete delivery operation illustrates the methodology of resource-interacted simulation modeling and its potential for “plug-in and simulate.”     

Non-Unit-Based Planning and Scheduling of Repetitive Construction Projects

Repetitive scheduling methods are more effective than traditional critical path methods in the planning and scheduling of repetitive construction projects. Nevertheless, almost all the repetitive scheduling methods developed so far have been based on the premise that a repetitive project is comprised of many identical production units. In this research a non-unit-based algorithm for the planning and scheduling of repetitive projects is developed. Instead of repetitive production units, repetitive or similar activity groups are identified and employed for scheduling. The algorithm takes into consideration: (1) the logical relationship of activity groups in a repetitive project; (2) the usage of various resource crews in an activity group; (3) the maintaining of resource continuity; and (4) the time and cost for the routing of resource crews. A sample case study and a case study of a sewer system project are conducted to validate the algorithm, as well as to demonstrate its application. Results and findings are reported.     

Organizational Alternatives for Large Projects

Organizing large construction projects can be as confusing and challenging as managing them. Many organizational variations are possible. This paper describes five major organizational alternatives and reviews the advantages and disadvantages of each. The alternatives include: (1) Strong functional organization; (2) functional organization with area coordination; (3) functional organization wth area management; (4) area management with craft discipline staff; and (5) autonomous area organization. This paper also proposes a method for selecting a project organization that involves developing organizational criteria and using these criteria in an evaluation matrix. Such a process could aid managers in meeting the challenge of effective project organization.     

Cranes for Building Construction Projects

Cranes have come to symbolize building construction itself. They perform indispensable services in moving materials and components vertically and horizontally. Used since antiquity, their history is interrelated with the development of new power sources that replaced man and mule, first steam and later internal combustion, diesel, and electric engines. Mobile cranes can be rapidly deployed to lift heavy loads. New models with telescoping booms and all-terrain travel capability, compact urban machines, and even hybrids with tower cranes are beginning to replace the familiar lattice boom truck cranes. Mobile cranes have dominated the North American market, but a cultural change appears to be taking place toward tower cranes for building projects. Tower cranes, common in Europe for decades, are globally gaining in popularity with surging real estate developments. Ideal for dense urban environments and coming with a small footprint, they are available in a growing diversity of sizes and configurations. Sophisticated electronic controls and operator assistance devices are enhancing their safe and productive operation. While cranes occupy a central role on midrise and high-rise building projects, they operate in conjunction with other types of supporting equipment that are an essential part of the overall equipment array on today’s industrialized construction sites.     

Measuring Effectiveness of Materials Management for Industrial Projects

A measurement of the effectiveness of the material management process is needed in order to analyze problems, suggest solutions, and assess the impact of modifications to the process. Such measurement is also required for any benchmarking effort. Research was conducted to apply a set of key effectiveness measures on 17 ongoing industrial projects. This research showed that most of the measures were easily obtainable, but some were difficult to obtain. Research also showed that it was possible to obtain the highest score on all measures, indicating that best practice in industry is achieving highly successful results. Most of the projects appeared to have a highly effective materials management process, as indicated by the fact that median values of these measures were much closer to the best values than those of the mean values. A utilization plan for the measurement of the effectiveness of the material management process is presented.     

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.     

Improving Cost Estimates of Construction Projects Using Phased Cost Factors

Central to cost-based competition is the capability to accurately predict the cost of delivering a project. Most literature on cost estimation focuses on specific estimation methods as generic techniques and little attention has been paid to the unique requirements at each project stage. This note attempts to identify the critical factors for effective estimation at various stages of typical construction projects. Drawing from organization control theory and cost estimating literature, this note develops a theoretical framework that identifies the critical factors for effective cost estimation during each project phase of a conventional construction project. The underlying logic is that as a cost estimating effort progresses, both task programmability and output measurability improve. As a result, control effort will shift from input-oriented control to a combination of output and behavior control.     

Application of Dependency Structure Matrix for Activity Sequencing in Concurrent Engineering Projects

The dependency structure matrix (DSM) has been identified as an apt tool to represent information flows between activities. Using this representation, information dependency attributes can be organized and analyzed in a structured manner to identify activity groups and sequences for concurrent execution. Current DSM methodology requires significant efforts from the experts to estimate information dependency attributes. The methodology can be more widely used if the estimating efforts are reduced. This paper proposes two concepts to reduce the estimating efforts required for the DSM methodology. The first concept reduces the number of information dependency ratings required and the second concept reduces the effort to estimate the rating. The proposed concepts are structured into a procedure. This procedure is applied to the design phase of an induced draft cooling tower (IDCT) project and discussed. The paper also discusses the shortcomings and future directions of the present approach and concludes that the present approach is applicable in IDCT projects and can be extended to other types of projects.     

Survey of the Construction Industry Relative to the Use of CPM Scheduling for Construction Projects

While critical-path method (CPM) scheduling has been around since the 1950s, its application in the construction industry has still not received 100% acceptance or consistency in how it is used. Project controls, and CPM scheduling in particular, have gone unchanged in the standards arena with little focus for a common understanding and recognition of what is required for CPM schedule development, implementation, and use. In recent years, little research has been conducted relative to the use of CPM and its benefits. In order to determine how the industry views its applicability and usage, a survey was developed for the stakeholders in the construction industry. This paper summarizes extensive research that was performed of the construction industry relative to the use of CPM scheduling, its applicability and its acceptance in the execution of today’s constructed projects. The research obtained the stakeholders’ views on the use and effectiveness of CPM scheduling; the necessary qualifications of scheduling personnel; and opinions relative to whether standards and/or best practices are necessary. The paper discusses the different views of the stakeholders and recommendations as to how consistency can be obtained in the use of CPM scheduling in order to improve the construction industry.     

Pilot Study of Quality Function Deployment in Construction Projects

Quality function deployment (QFD) is a process that has been used for managing the development of new manufactured products. In this process, both spoken and unspoken needs of the customers are determined, prioritized, and translated to design parameters. Such design parameters are assigned specific target values and are frequently checked against customers’ needs throughout the development cycle to ensure customers’ satisfaction with the end product. This paper describes a pilot study in which QFD was implemented in a design-construction project. The project scope involved the preparation of a conceptual design for a modern large-size classroom for college students. The design was intended to become a model for the university’s future classrooms. The study proved that QFD could be successfully adopted in engineering-construction projects. However, the study identified a number of implementation challenges. In addition, more applications are necessary to take the process throughout the full project delivery cycle, as the pilot study involved only the preliminary engineering and conceptual design phase.     

Dispute Review Boards: Expected Application on Egyptian Large-Scale Construction Projects

The construction industry is heavily affected by the troubles arising out of construction disputes, especially when it comes to large-scale projects, as a direct result of the inherent complexity of such projects. This paper seeks the most suitable dispute-resolution mechanism for large-scale construction projects in Egypt, which is a developing country in the Middle East with an emerging reformed economical policy, a population in excess of 70 million people, and an increasing need for infrastructure and industrial development. This dispute-resolution mechanism was attained through a multistep methodology that (1) started with the study of the Arbitration process in relation to an Egyptian construction project with an initial contract price of 85 million; (2) continued with interviews of five senior experts in the field of construction disputes in Egypt about their views pertaining to the most efficient dispute-resolution methodology for Egyptian megaprojects; (3) developed a tailored questionnaire to assess the perceptions of 35 professionals toward the issue of construction disputes and dispute resolution mechanisms, including DRB; (5) concluded by carrying out a what-if scenario for the arbitration case of the large-scale construction project using DRB instead of arbitration. On basis of the analysis of the methodology, the authors concluded that despite the wide range of current dispute-resolution methodologies, the employment of DRBs in accordance with a set of 13 regulatory guidelines should mitigate the negative effects of disputes in Egyptian large-scale construction projects. Accordingly, this paper is both timely and valuable for all owners, contractors, and professionals who are acquainted with Egyptian megaprojects.