Evaluating Cost Overruns of Asphalt Paving Project Using Statistical Process Control Methods

While some projects will experience changes to the contracted cost by deduction or additions, construction cost overruns are becoming a common problem in the construction industry. Steps need to be taken to minimize cost overrun through cost and quality control techniques. This paper presents a study conducted to evaluate construction cost overruns of asphalt paving operations performed by the Illinois Department of Transportation (IDOT). The main objective is to analyze the main causes of cost overruns and evaluate the amount of cost overrun of asphalt paving operations, using statistical process control (SPC) techniques. Real data from projects in the year 2000 were collected from IDOT. These data contain cost information of 219 projects. The results indicate that the average cost overrun for the sample collected was 4% above the bid price. Reasons for cost overruns are analyzed and a Pareto chart and a cause and effect diagram are constructed. Individuals and Moving Range (MR) control charts are developed and their interpretation and use are discussed. Furthermore, the benefits and limitations of using the individuals and MR chart in cost control applications are pointed out. It is recommended that SPC analysis be an integral part in managing and controlling project costs.     

3D Scan Information Management System for Construction Management

This paper presents an internet-based three-dimensional (3D) scan information management system (3DSIMS) that can be used as an interface to input, display, and inspect design as-built construction information. This system is mainly developed using 3D scan data. The function of the 3DSIMS is to integrate the scan data collected before, during, and after a scan scheme that is designed to capture as-built 3D records. The information included in this system consists of a scan scheme, scanned point clouds, construction records, and postscan processed clouds for the display, search, and comparison of scans made each week during the construction of a campus building. This study represents a long-term effort that has rarely been done before. A web page is used to deliver and share scan information. The feasibility of this approach is explained by the examples of dimension-related checks through as-built data.     

Total Quality Management for Construction

Traditional approaches to quality control in the construction industry are inadequate and should be replaced with the Total Quality Control concept implemented through the Quality Control (Q.C.) Circle as developed in Japan and currently in wide use throughout the manufacturing industry. The term “total quality control” is defined, and four total quality control principles are set forth on the basis of this definition. The evolution of quality control is traced from the nineteenth century to today to explain the decline in quality standards and to illustrate the need for a new approach. Unique characteristics of the construction industry are described as they relate to the Q.C. circle concept. Implementation of this concept will result in higher quality, lower costs, and increased productivity in the construction industry.     

Construction Management Control with Microcomputers

The development of microcomputers is changing the nature of common construction management functions. The estimating function can now be used with greater ease to simultaneously evaluate the time required to perform different project activities and keep cost data related to cost control. While this procedure was time consuming for manual computation, it could be done in a reasonable amount of time when using microcomputers. This paper discusses the formation of a microcomputer system which can perform the functions of estimating, cost control, and scheduling at the same time. The procedure makes use of productivity of a crew of particular size, the materials and the equipment needed, to generate time data related to scheduling and cost data related to estimating and cost control. The software needed for implementing the system is an electronic spreadsheet program, a data base management program and a time management program available for most microcomputers at a relatively inexpensive cost.     

Pavement Life-Cycle Cost and Asphalt Binder Quality: Theoretical and Experimental Investigation

Quality control/quality assurance tests can be used to demonstrate that an as-constructed pavement has characteristics different from the contracted specifications of the as-designed pavement because the bitumen employed was of insufficient quality. Many different issues affect asphalt binder quality. Such problems can significantly increase the pavement life-cycle cost, which means that a pay adjustment (PA) is needed. Unfortunately, the quantitative analysis of this issue is very complex. The objectives of this study were to model the dependence of the pavement life-cycle cost on asphalt binder quality and to determine the quantitative relationship between bitumen viscosity and the PA for a given class of boundary conditions. In addition to modeling this problem theoretically, experiments and simulations were carried out through the use of the Mechanistic-Empirical Pavement Design Guide. We then derived the consequences of these effects on life-cycle cost by using a specific life-cycle cost model. Our results demonstrate that asphalt binder viscosity can strongly affect the expected pavement life and the PA, and thus needs to be taken into account in contract and construction management.     

Time of Sampling Strategies for Asphalt Pavement Quality Assurance

The cost of quality assurance programs in asphalt road construction is high in part because of the need for daily testing. This paper demonstrates the methodology used to investigate the timing of sampling and its effect on the quality assurance program. Fourteen lots over two highway paving projects were tested twice: during construction on a daily basis, and after construction was complete. Three quality measures were compared, namely asphalt content, degree of compaction, and aggregate gradation. The test data during construction were obtained from two sources: the consultant’s quality assurance, and the contractor’s quality control. One-way ANOVA tests and T-tests were used to compare the means. In addition, the arithmetic difference between the means was reviewed to understand how the time of sampling might affect contractor payment adjustments.     

Implementing Total Quality Management in Construction Firms

As building projects get larger and more complex, clients are also increasingly demanding higher standards for their delivery. Total quality management (TQM) has been recognized as a successful management philosophy in the manufacturing and service industries. TQM can likewise be embraced in the construction industry to help raise quality and productivity. Two case studies of construction companies showed how TQM can be successfully implemented in the construction industry. The benefits experienced include reduction in quality costs, better employee job satisfaction because they do not need to attend to defects and client complaints, recognition by clients, work carried out correctly right from the start, subcontractors with proper quality management systems, and closer relationships with subcontractors and suppliers. TQM performance measures were also reflected through top management commitment, customer involvement and satisfaction, employee involvement and empowerment, customer–supplier relationships, and process improvement and management. Finally, a framework for implementing TQM in construction is recommended.     

Fundamental Principles of Site Material Management

This paper was written to fill a void created by the absence of fundamental principles of site construction management. Efficient material management is essential to managing a productive and cost efficient site. For more than 25?years, the senior author has been observing and writing about inefficient labor productivity practices resulting from poor site material management. Using deductive reasoning, fundamental principles were developed to avoid poor practices. A construction site should be portioned into three areas or zones: semipermanent (exterior) storage, staging areas, and workface (interior) storage. Each has a unique function relative to site material management. Using these areas as a framework, fundamental principles are stated and illustrated using a case study project accompanied by numerous photographs and narratives.     

Prediction System for Change Management in Construction Project

Changes are the main causes of delays and cost overruns in construction projects. Various change management systems have been developed to minimize the impacts of changes and to facilitate good project management. This paper presents a change prediction system using activity-based dependency structure matrix (DSM) to facilitate change management. DSM is used to model the process that may occur as a result of changes. Consequently changes can be predicted by setting the change criteria for each activity in the form of rework scope. Furthermore, Monte Carlo simulation is introduced to analyze the change probability of activities involved in construction projects. The effectiveness of the prediction system is verified by applying this system to an office building project. This study provides a useful tool for project management teams to manage changes proactively and efficiently.     

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.     

Multiproject Planning and Resource Controls for Facility Management

Facility managers face the challenges of managing many different types of small, geographically dispersed construction projects. Depending on the complexity and distribution of projects, the time required to prepare for production consumes a large percentage of the total time required to complete the job. Increasing crews’ productive hours is a key objective when planning multiproject schedules. Existing methods, however, lack the effective means to explicitly model, analyze, and optimize resource utilization for these multiple concurrent projects. As a result, few facility managers fully exploit the potential to better manage their often limited budget and resources. This paper presents an explicit model of the mobilization requirements of multiple crews performing a variety of different activities over a geographic space. The model allows the facility manager to explicitly investigate the impact of crew composition, crew specialization, and depot locations. Using work rule decisions regarding alternative crew allocations, facility managers may dynamically allocate resources to optimize resources and to complete projects in a minimum amount of time. To verify and validate this new model, a computerized system, called FIRS (Facility/Infrastructure Resource Scheduler), was created to analyze the multiproject resource plans with data from two military organizations and a university campus. FIRS utilizes a new genetic algorithm that was developed specifically to work with multiproject scheduling. Using FIRS, facility managers can develop and test alternative crew allocations based on the qualifications of the crews available and the type of operation being performed.     

Management of Daily Progress in a Construction Project of Multiple Apartment Buildings

This paper presents the methods used and a case study of a project management system (PMS) to manage daily progress in the construction of multiple apartment buildings in South Korea. A dilemma encountered in previous research in the field of progress management is that efforts to enhance data accuracy cause the data handling workload to soar. A main feature of the method presented by the writers for calculating the budgeted cost work schedule is to allocate the project budget into control attributes, activities, and tasks that are defined in a work-packaging model, according to daily weight value. The method offers enhanced practicability by reducing data-handling workloads while not sacrificing the rationale of progress management. The work-packaging model is designed to enable project managers to acquire and process data for progress management at various levels of detail. The budgeted cost of work performed is measured daily at the tasks level using the earning percentage rate from daily work reports. The implementation of PMS focuses on functions to distribute the budget according to daily weight values and acquire the earning percentage from the daily work report. The PMS was applied to a construction project of 54 apartment buildings in South Korea. The case study of its use shows that company headquarters and managers in the field can acquire data for progress management without additional data-handling workloads, and can analyze the progress daily at various levels of detail.     

Effects of Schedule Pressure on Construction Performance

Accelerating a project can be rewarding. The consequences, however, can be troublesome if productivity and quality are sacrificed for the sake of remaining ahead of schedule, such that the actual schedule benefits are often barely worth the effort. The tradeoffs and paths of schedule pressure—and its causes and effects—are often overlooked when schedule decisions are being made. This paper analyzes the effects that schedule pressure has on construction performance, and focuses on tradeoffs in scheduling. A research framework has been developed using a causal diagram to illustrate the cause-and-effect analysis of schedule pressure. An empirical investigation has been performed by using survey data collected from 102 construction practitioners working in 38 construction sites in Singapore. The results of this survey data analysis indicate that advantages of increasing the pace of work—by working under schedule pressure—can be offset by losses in productivity and quality. The negative effects of schedule pressure arise mainly by working out of sequence, generating work defects, cutting corners, and losing the motivation to work. The adverse effects of schedule pressure can be minimized by scheduling construction activities realistically and planning them proactively, motivating workers, and by establishing an effective project coordination and communication mechanism.     

Navigational Models for Computer Supported Project Management Tasks on Construction Sites

Integrated product and process models have started gaining acceptance in the construction industry and it is conceivable that in the near future project data will be contained in these models. A project model can contain large data sets making it harder for users to navigate. This challenge is even more difficult in cases where mobile computing is used on site for accessing and collecting data needed for a construction management task. Navigational models are constructs that provide construction personnel, who are using mobile computing applications on construction sites, with information and data collection support relevant to their tasks and environments. Navigational models provide a flexible and dynamic way of grouping and structuring entities of product and process models such that those entities that need to be related for one task are linked directly to minimize the navigation through a given model. Moreover, navigational models provide a way to structure the data contained in product and process models in hierarchies facilitating interaction with entities at multiple levels of detail. In this paper, we describe construction site-based project management tasks and demonstrate how navigational models can facilitate efficient data access and data collection processes by customizing the presented information for a given task and environment of a user.     

Testing of Minimization of Subjectivity in Best Value Procurement by Using Artificial Intelligence Systems in State of Utah Procurement

The Performance Information Procurement System (PIPS) was tested on the procurement of the $2.96 million Bridgerland Academic Training Center (ATC) for the state of Utah Division of Facilities Construction Management. The artificial intelligence (AI) information based PIPS was run two ways—selection with biased subjectivity (similar to current best value processes) and without biased subjectivity. Unlike other best value processes, PIPS minimizes the decision-making and subjective bias of the owner’s representatives. The procurement test at Bridgerland ATC provides a comparison between the AI selection versus the user agency’s subjective prioritization. The result of the system was one of the “best” construction projects procured at the state of Utah (on time, on budget, high quality), with no contractor generated change orders for additional cost, minimized construction management requirements, and high customer satisfaction.     

Automated Generation of Work Spaces Required by Construction Activities

To provide a safe and productive environment, project managers need to plan for the work spaces required by construction activities. Work space planning involves representing various types of spaces required by construction activities in three dimensions and across time. Since a construction schedule consists of hundreds of activities requiring multiple types of spaces, it is practically impossible to expect project managers to specify manually the spatiotemporal data necessary to represent work spaces in four dimensions. This paper presents mechanisms that automatically generate project-specific work spaces from a generic work space ontology and a project-specific IFC (industry foundation class) based 4D production model. The generation of these work spaces leads to a space-loaded production model. Within this model, work spaces are represented as being related to the relevant construction activities and methods and as having attributes that describe when, where, and how long they exist, and how much volume they occupy. These space-loaded production models enable richer 4D CAD simulations, time-space conflict analysis, and proactive work space planning prior to construction.     

Steel Construction Evaluation by MLR‐Strategies

Improvements in design, achieved through a better understanding of fabrication costs, may cause an overall cost reduction for steel structures. Multiple Linear Regression (MLR) provides the mechanism for transformation of data collected by an information system to data which is used in the evaluation of structural steel fabrication costs. The integration of fabrication control and analysis provided by this system permits its implementation in existing fabrication environments, and presents a desperately needed technological gain for the fabrication process. Traditional design approaches which have relied heavily on experience can now be evaluated and improved in terms of cost competitiveness, prior to or during fabrication by the proposed MLR strategy.