Illustrative Benchmarking Rework and Rework Costs in Swedish Construction Industry

Following several studies investigating the causes of construction rework among some projects in the Swedish construction industry, we conducted this study in cooperation with R&D West, a group of construction companies in Sweden, to measure the costs of rework in construction projects. Rework has become an endemic feature of the procurement process in construction that invariably leads to time and cost overruns in projects. Thus, in order to improve the performance of projects, it is necessary to identify the causes and costs of construction rework. The research presented in this paper identifies, analyzes, and discusses the causes, magnitudes, and costs of rework experienced in seven Swedish construction projects. The findings revealed that the costs of rework for the case study projects were 4.4% of the construction values of the observation period, and the time needed to correct them was 7.1% of the total work time. The construction errors that generated rework were further analyzed according to their origins, types, and positions, causes of construction rework were identified and discussed, and preventive actions were suggested.     

Selection of Project Delivery Method in Transit: Drivers and Objectives

This paper describes the results of research on alternative project delivery methods in transit projects in the United States. The research, sponsored by the Transit Cooperative Research Program, aimed to identify those factors that drive the decision in the choice of project delivery method. A rigorous case study analysis based on on-site structured interviews with the directors of several transit projects was used to identify decision drivers and the rationale behind the delivery method selection decision in transit agencies. The nine case studies conducted in this research represent a cross section of delivery methods, including design-bid-build/multiprime, construction manager-at-risk, design/build, and design/build-operate-maintain. The interviewees agreed that the use of alternative delivery methods have resulted in savings in schedule and cost for transit agencies. The research also found that achieving aggressive schedule compression is the most influential factor when selecting alternative delivery methods. Also, implementation of a formal risk analysis as part of the project development process appears to improve the project’s chances of meeting budget and schedule objectives.     

Reasons for Cost and Schedule Increase for Engineering Design Projects

Cost and schedule increases are common in engineering design projects. Some research has studied factors associated with better design performance, but the reasons for cost and schedule increases are not formally investigated. This paper identifies the reasons bottom up from four case project documents and further quantifies their contributions to cost and schedule increases. These reasons are complete and can be used to analyze the cause-effect relationship, trace responsibility, and improve performance for engineering design projects.     

Benchmarking, Benchaction, and Benchlearning: Rework Mitigation in Projects

The Australian government has issued several calls to improve the performance of the construction industry. A lack of available benchmark metrics has made it difficult, if not impossible, for organizations to identify areas to target for process improvement. A significant factor that has been found to contribute to poor organizational and project performance is rework. Using the results of a questionnaire survey, the paper presents and discusses a series of benchmark metrics for the causes and costs of rework for 161 construction projects. A generic framework for benchmarking rework at the interfaces of a project’s life cycle is proposed, and unstructured interviews are used to subject the proposed framework to validation by industry practitioners.     

Decision Tool for Selecting the Optimal Techniques for Cost and Schedule Reduction in Capital Projects

Projects must meet budget, schedule, safety, and quality goals to be regarded as a success. Many factors come into play, and many decisions are made that influence a project’s outcome. Today, owners are often faced with deciding between an execution strategy that emphasizes either project cost or project schedule. Such a decision may be made not once, but throughout the life of the project. Project teams, when required by the owner to make a cost-schedule trade-off, generate common sense ideas, best practices, and other means of achieving the desired trade-off through brainstorming sessions. This paper offers a tool for systematically identifying the techniques which are most effective in achieving the trade-off goal. Project teams can then use these techniques in a timely fashion to increase the likelihood of project success.     

Procurement Routes in Public Building and Construction Projects

This paper deals with procurement routes in public building and construction projects in Norway. Seen from a practical point of view, as well as from a theoretical one, it is important to improve methods for selection of procurement procedure, contract model, and compensation formats. The paper objective is to find out if public owners select a procurement route according to recommended practice. The sources are literature, support material for two software tools for selection of the procurement route, and documentation from 22 public building and construction projects in Norway. According to the literature and the support material for the two software tools, the answer to what is the proper procurement route will depend on the characteristics of each project. The documentation study implies that public owners continue to select the same procurement route as they are in the habit of. They do not consider what procurement route suits each single project, and therefore they do not select the route according to recommended practice. The paper calls for innovation and better supported selection of the procurement route in public building and construction projects.     

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.     

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.     

Evaluation of Risk Factors Leading to Cost Overrun in Delivery of Highway Construction Projects

Accurate owner budget estimates are critical to the initial decision-to-build process for highway construction projects. However, transportation projects have historically experienced significant construction cost overruns from the time the decision to build has been taken by the owner. This paper addresses the problem of why highway projects overrun their predicted costs. It identifies the owner risk variables that contribute to significant cost overrun and then uses factor analysis, expert elicitation, and the nominal group technique to establish groups of importance ranked owner risks. Stepwise multivariate regression analysis is also used to investigate any correlation of the percentage of cost overrun with risks, together with attributes such as highway project type, indexed cost, geographic location, and project delivery method. The research results indicate a correlation between the reciprocal of project budget size and percentage cost overrun. This can be useful for owners in determining more realistic decision-to-build highway budget estimates by taking into account the economies of scale associated with larger projects.     

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.     

Cost and Schedule Monitoring of Industrial Building Projects: Case Study

Performance measurement is a helpful tool for taking corrective actions and controlling a project as far as this enables accurate time and cost forecasts during the first stages of the construction effort when the management team still has opportunities to make adjustments. This paper overcomes the dilemma of practicability and predictability of traditional estimates at completion based on early progress measurement by presenting the empirical results from the construction project of an industrial facility. The case may be a reference practice for assessing time and cost performance measurement of any building, whose layout can be reasonably partitioned into repeatable portions. In such circumstances, an effectively-managed traditional earned value method and appropriate metrics for computing performance provide project managers with accurate forecasts as useful tools for successful project management and control.     

Causes, Effects, Benefits, and Remedies of Change Orders on Public Construction Projects in Oman

Change orders are usually issued to cover variations in scope of work, material quantities, design errors, and unit rate changes. This paper discusses variations in public construction projects in Oman by investigating causes of variations, studying their effects on the project, identifying the beneficial parties, and suggesting remedies to alleviate related problems. Tasks included an analysis of four actual case studies and conducting a field survey via a questionnaire. It was determined that the client’s additional works and modifications to design were the most important factors causing change orders, followed by the nonavailability of construction manuals and procedures. The most important effects of change orders on the project were found to be the schedule delays, disputes, and cost overruns. The contractor was found to be the party most benefiting from the change orders followed by the consultant and then the client. A set of remedial actions were suggested and respondents viewed that the revision of registration of consulting offices would be the most important action followed by establishing standard documents for design procedures and building a national database about soil conditions and services.     

Data Preprocessing–Based Parametric Cost Model for Building Projects: Case Studies of Korean Construction Projects

For construction to progress smoothly, effective cost estimation is vital, particularly in the conceptual and schematic design stages. In these early phases, despite the fact that initial estimates are highly sensitive to changes in project scope, owners require accurate forecasts which reflect their supplying information. Thus, cost estimators need reliable estimation strategies. In practice, parametric cost estimation, which utilizes historical cost data, is the most commonly used method in these initial phases. Therefore, compilation of historical data pertaining to appropriate cost variance governing parameters is a prime requirement. However, data mining (data preprocessing) for denoising internal errors or abnormal values must be performed before this compilation. To address this issue, this research proposes a statistical methodology for data preprocessing. Moreover, a statistically preprocessed data–based parametric (SPBP) cost model is developed based on multiple regression equations. Case studies of Korean construction projects verify that the model enhances cost estimate accuracy and reliability than conventional cost models.     

Critical Factors Affecting Schedule Performance: Evidence from Indian Construction Projects

Over 40% of Indian construction projects are facing time overrun ranging from 1 to 252 months; the reasons for which are being studied by researchers to suggest possible remedial measures. This paper identifies 55 attributes responsible for impacting performance of the projects. These attributes were then presented to Indian construction professionals in the form of a questionnaire. Statistical analysis of responses on the attributes segregated them into distinct sets of success attributes and failure attributes. Factor analysis of sets of success attributes and failure attributes separately grouped them into six critical success factors and seven critical failure factors. In order to understand the extent of contribution these factors have on the outcome of a construction project, a second stage questionnaire survey was also undertaken. The analyses of responses of the second stage questionnaire led us to conclude that two success factors and one failure factor: commitment of project participants; owner’s competence; and conflict among project participants contribute significantly in enhancement of current performance level of the project. The extent of their contribution has, however, been observed to vary for a given level of project performance. The analyses results are expected to help project professionals to focus on a few factors and get the optimum results rather than giving attention to all the factors and not getting the proportionate results.     

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.     

Agent-Based Compensatory Negotiation Methodology to Facilitate Distributed Coordination of Project Schedule Changes

Change is ubiquitous in construction project schedules and there are many interrelationships and interdependencies in project schedule changes. Therefore, a schedule change in the work of a subcontractor might affect schedules of other subcontractors, as well as the project deadline. The subcontractor should resolve schedule conflicts with other affected subcontractors. This implies that there is a need for a methodology for the distributed coordination of project schedule changes (DCPSC). This paper presents a novel agent-based compensatory negotiation methodology to facilitate the DCPSC wherein a project can be rescheduled dynamically through negotiations by all of the concerned subcontractors. The methodology consists of a compensatory negotiation strategy based on utility of timing, multilinked negotiation protocols, and message-handling mechanisms. A simple case example illustrates the methodology. The methodology makes new contributions in both theoretical and practical areas. In practice, this methodology will improve project network schedules, by lowering the sum of the cost of the subcontractors associated with their resource constraints. In theory, the methodology provides a distributed coordination methodology that can improve interaction and collaboration among agents and people.     

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.     

In-House Delivery of Multiple-Small Reconstruction Projects

As compared with new construction, reconstruction of operational facilities exhibits a higher challenge, particularly when multiple projects are involved. For owner organizations involved in such projects, use of in-house resources versus outside contractors has been a major dilemma, with each approach having its potential benefits. This paper uses a real-life case study approach to investigate the delivery of 800 small reconstruction projects using in-house forces. Details are described related to the prioritization, budgeting, organization structure, and the mechanisms used for staff allocation. It was found that the main characteristics of projects that are best delivered by in-house forces include high urgency and inadequate scope definition. Outsourcing this type of projects exposes the owner to a large number of changes and their consequent cost overruns/delays. Based on the case study, the challenges facing in-house delivered projects and the factors that contribute to their success were investigated and outlined. To verify the findings a questionnaire survey among similar organizations is conducted and its results discussed.     

Rework in Civil Infrastructure Projects: Determination of Cost Predictors

Within Australia, civil engineering works continue to meet the insatiable demand for new infrastructure despite project complexity and cost and schedule overruns. A significant factor that can contribute to such overruns is rework; yet to date research into the root causes and consequential costs of rework in civil infrastructure projects has been limited. Using a questionnaire survey, rework costs and probable causes were obtained from 115 civil infrastructure projects. Stepwise multiple regression was then used to determine the significant variables that contributed to rework. The regression model revealed that the following five significant predictors accounted for 25% of the variance in total rework cost: (1) ineffective use of information technologies; (2) excessive client involvement in the project; (3) lack of clearly defined working procedures; (4) changes made at the request of the client; and (5) insufficient changes initiated by the contractor to improve quality. The findings also revealed that mean total rework costs were 10% of the contract value for the sample. Interestingly, the extent of rework experienced was significantly correlated with project cost and schedule growth (p<0.01). It is suggested that future work is required to determine the underlying factors that contribute to rework in civil infrastructure projects before effective preventive strategies can be identified.