Analysis of the Design-Build Delivery Method in Air Force Construction Projects

The design-build (DB) method for construction project delivery continues to grow in both the private and public sector; additionally, research has shown that the DB method outperforms the design-bid-build (DBB) method. The Air Force has applied the results of these previous research efforts to its military construction (MILCON) program without performing empirical studies to validate the approach. Therefore, the objective of this study was to compare the performance of the DB delivery method with the traditional DBB approach for the Air Force MILCON program. Data related to 835 (278 DB and 557 DBB) MILCON projects for fiscal years 1996–2006 were subsequently analyzed. The DB method had better performance in three of six metrics with the performance being significantly better for cost growth and the number of modifications per million dollars. The traditional DBB method performed significantly better in terms of total project time. Furthermore, the DB method was best suited for various facility types. This study provides empirical evidence of how the DB method provides an advantage over the traditional DBB method for Air Force MILCON projects.     

Cost Analysis between SABER and Design Bid Build Contracting Methods

The majority of Air Force construction is performed by two main contractual methods, design bid build (DBB) and simplified acquisition of base engineering requirements (SABER). DBB is the traditional contracting method in which each project is competitively bid. SABER uses one contractor to complete multiple projects using unit prices established in the original contract. This research performs a cost analysis between DBB and SABER construction projects. The research involved finding appropriate, comparable projects completed by the two contractual methods. Two diverse Air Force bases were used to gather project information, and a total of 46 interior renovation projects were used. Project comparability was demonstrated by evaluating the similarity of type and scope of work. Data from the projects was used to calculate unit cost per dimensional characteristic and time and cost growth for each project. The results indicated SABER contracting had a lower cost per square meter, although not at a statistical level of significance. SABER performed better in time growth. Cost growth was similar for both methods.     

Predicting Performance of Design-Build and Design-Bid-Build Projects

Design-build (DB) and design-bid-build (DBB) are two principal project delivery systems used in many countries. This paper reports on models constructed to predict performance of DB and DBB projects on 11 areas, using project-specific data collected from 87 building projects. The study included collecting, checking, and validating industry data, and the statistical development of multivariate linear regression models for predicting project performance. Robust models are developed to predict construction and delivery speeds of DB and DBB projects. Gross floor area of the project is the most significant factor affecting speed. Besides this, for DBB projects, contractors’ design ability, and adequacy of plant and equipment would ensure speedy completion of the projects. For DB projects, if the contract period is allowed to vary during tender evaluation, this would slow down the project. Robust models to predict turnover and system quality of DB projects are also constructed. A DB contractor’s track record is an important variable. They must have completed past projects to acceptable quality and have ability in financial, health and safety management.     

Effect of Delivery Methods on Design Performance in Multifamily Housing Projects

Existing studies on the performance evaluation by the delivery method generally indicate that the design build (DB) method is superior to the design-bid-build (DBB) method in terms of construction duration, cost, and quality. As opposed to the performance of construction duration and cost, where quantitative evaluation is relatively possible, most performance evaluations of quality are based on interviews with the owners. Therefore, this paper aimed at evaluating the level of design performance to conduct a quantitative evaluation on the performance of quality. To achieve this goal, this paper analyzed the impact of delivery methods on design performance in terms of the quantitative evaluation based on the case studies analyzing construction drawings and specifications of public multifamily housing projects delivered through the DB and DBB methods since 2000. The Delphi and analytic hierarchy process methods were used to develop objective standards and contents for evaluating the design performance. An analysis of variance test was conducted to analyze which delivery methods would have an effect on the design performance. Construction industry practitioners can use the results of this study in selecting a delivery method appropriate to the project characteristics.     

Greening Project Management Practices for Sustainable Construction

Environmentally sustainable building construction has experienced significant growth during the past 10 years. The public is becoming more aware of the benefits of green construction as prominent politicians, celebrities, documentarians, and journalists highlight the built environment’s impact on greenhouse gas emissions and natural resource consumption. Other factors, including higher energy prices, increased costs of building materials, and regulatory incentives, are also pushing the green building market to grow and expand. However, barriers to green building continue to exist, including the ability to deliver a green project within acceptable cost constraints. In order for project managers to deliver sustainable construction according to clients’ cost expectations, modifications must be made to traditional project management processes and practices. The objective of this paper is to suggest specific modifications to conventional building practices to optimize the delivery of cost-efficient green building projects. This paper presents an overview of research related to the costs and trends of green building and uses these research findings to make recommendations for greening project management practices for the construction industry. Our research results show that greening project management practices can add significant value to a sustainable construction project while delivering it within acceptable cost constraints. A detailed analysis using matrix present specific adjustments to traditional project management practices, with a premise that a green project improves its chances for financial success if a cross-discipline team is involved at the earliest stages and throughout the project.     

Cost Performance Comparison of Two Public Sector Project Procurement Techniques

Increased industry discussion of the potential benefits of alternative forms of construction project delivery often presents little cost analysis of options. This work presents the results of a cost comparison study of completed public sector municipal facilities design and construction projects—a portion of which delivered using a traditional design-bid-build procurement approach and a portion of which delivered using the procurement technique of a negotiated lump sum construction contracts with in-house construction forces. The study compares costs for all phases of all the projects (design, bid and award, construction, and total project cost) across both methods of project procurement. Conclusions examine the cost trade-offs of using negotiated contracts with in-house forces, outline key success factors identified through this study in order to optimize the use of this form of project procurement, and identify areas for future research.     

Analysis of Owner’s Design and Construction Quality Management Approaches in Design/Build Projects

This paper explores and classifies current approaches to evaluating quality in design/build (DB) proposals. It does so by a thorough content analysis of 78 requests for proposal (RFPs) for public DB projects with an aggregate contract value of over $3.0 billion advertised between 1997 and 2002. In most DB projects, the owner requires the DB contractor to establish a firm-fixed price on a project that has not yet been designed. Usually, the owner also fixes the project delivery period. In the traditional design/bid/build (DBB) system, quality is fixed through the plans and specifications. Thus, in DBB, with schedule and quality fixed, the cost of construction is the factor in which the owner seeks competition. Conversely, in DB, with cost and schedule fixed, the scope and hence the level of quality is the main element of competition. This paper identifies the six owner approaches to articulating DB quality requirements in their RFPs. The six approaches are quality by qualifications, evaluated program, specified program, performance criteria, specification, and warranty. These are important for DB contractors to understand so that they can craft their proposal in a manner that is both responsive to the owners’ requirements and consistent with the owner’s system to make the best value contract award decision.     

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.     

Divergence or Congruence? A Path Model of Rework for Building and Civil Engineering Projects

Rework has been identified as a major contributor to cost and schedule overrun in construction projects. Previous studies that have examined rework are based on a limited data sets and thus eschew generalizations being made about the key determinants. Using data from 260 completed building (n = 147) and civil engineering (n = 113) projects, path analysis is used to develop a structural model of the most significant causes of rework. The model revealed that the paths of client-directed changes, site management and subcontractors, and project communication were statistically significant contributors to rework costs. The analysis confirmed that the lack of attention to quality management resulted in higher rework costs being incurred in the projects sampled. The analysis also revealed that there were no significant differences between building and civil engineering projects in terms of the direct and indirect cost of rework experienced, and the effectiveness of the project management practices implemented. Considering the findings, it is suggested that generic strategies for reducing the incidence rework in construction and civil engineering projects can be developed.     

Influence of Project Type and Procurement Method on Rework Costs in Building Construction Projects

While it is widely recognized that additional costs due to rework can have an adverse effect on project performance, limited empirical research has been done to investigate the influencing factors. The research presented in this paper aims to determine the influence of different project types and procurement methods on rework costs in construction projects. Using a questionnaire survey, rework costs were obtained from 161 Australian construction projects. The direct and indirect consequences of rework are analyzed and discussed. It is shown that, contrary to expectation, rework costs do not differ relative to project type or procurement method. In addition, it was found rework contributed to 52% of a project’s cost growth and that 26% of the variance in cost growth was attributable to changes due to direct rework. To reduce rework costs and therefore improve project performance, it is posited that construction organizations begin to consider and measure them, so that an understanding of their magnitude can be captured, root causes identified, and effective prevention strategies implemented.     

Empirical Comparison of Design/Build and Design/Bid/Build Project Delivery Methods

This study compares the performance of design/bid/build and design/build to see if one project delivery method is superior in regards to time and cost. Similar military buildings were used to identify two samples of projects delivered with each of the two delivery methods. These projects provide a meaningful comparison because they include buildings of the same typology (i.e., U.S. Navy Bachelor Enlisted Quarters) delivered using similar design models. Project duration, project duration per bed, project time growth, cost growth and cost per bed were statistically compared. Upon completion of the analysis, the hypothesis that design/build projects are superior to design/bid/build projects in regards to time and cost was tested. Design/build projects were proven superior in performance in almost every measure. Other findings, including recommendations to practitioners and researchers, will be provided as well.     

Avoiding Change Orders in Public School Construction

Increased student enrollment and the current poor state of the educational infrastructure require the construction of more school buildings and the renovation of many of the existing ones. The large number and magnitude of change orders in these projects constitute an impediment to the rapid and economic delivery of these projects. A total of 6,585 change orders filed in a school district’s projects in the 5 1/2 year period from 1999 to 2004 were analyzed in five categories including owner-directed changes, code compliance issues, errors/omissions in contract documents, discovered or changed conditions, and others. The results of the study indicate that the dollar value of change orders relative to the original contract can be reduced if preventive measures are taken. These measures include choosing the right construction management firm, emphasizing the definition of project scope early in the project, and effectively managing the precontract activities by conducting value engineering and constructability reviews. The results indicate that school projects can be completed with change orders not exceeding 5% of the contract value if these measures are taken. This study is of relevance to practitioners involved in school design and construction projects.     

工程项目管理中的成本管理

工程项目成本管理是为保障项目实际发生的成本不超过项目预算而开展的项目资源计划、项目成本估算、项目预算编制和项目预算控制等方面的管理活动。是保证施工企业正常经营的重要的基础管理工作。     

Outside the Budget Box—Public/Private Partnership as a Creative Vehicle for Finance and Delivery of Public School Facilities

Our public schools face almost irresistible pressures to upgrade and expand facilities and deliver better, more advanced, and higher-quality education while tax revenues and therefore budgets are shrinking each year. Class sizes grow in old and outdated facilities, and municipalities and school districts have few resources to address the pressing space needs. There is little public support for increased funding. However, there is a way to deliver educational facilities that uses less public capital than traditional project finance. Public/Private Partnership (PPP) is a delivery method that has traditionally been used on large infrastructure projects in developing nations, in order to allow more development for less public capital investment while maintaining the overall quality of construction. In recent years, PPP has gained acceptance in Europe and now in the United States as a means of public school finance and construction. This paper discusses PPP, its fundamental principles, and the various ways it can be employed in the delivery of educational facilities, as well as its advantages and disadvantages.     

SIM-UTILITY: Model for Project Ceiling Price Determination

Before considering bids submitted by competing contractors for a public procurement project, the owner should determine a project ceiling price or cost estimate to use as a reference point for evaluating the bids. A high ceiling price conflicts with the owner’s interests in minimizing costs. Meanwhile, a low ceiling price can jeopardize the project if all bids exceed the ceiling price. This paper proposes a model for determining a reasonable project ceiling price. The model, called SIM-UTILITY, is based on a utility theory and facilitated by a cost simulation approach. The utility theory is applied to reflect the owner’s preferences regarding the determination criteria, while the simulation approach is used to generate more objective project cost data to support execution of the utility theory. The advantages of SIM-UTILITY are proven by its successful application to three construction projects in Taiwan. A computerized SIM-UTILITY is expected to be broadly applicable to public construction projects in Taiwan.     

Empirical Study of the Risks and Difficulties in Implementing Guaranteed Maximum Price and Target Cost Contracts in Construction

Over the past few decades, both the guaranteed maximum price (GMP) and target cost contracting (TCC) arrangements have been regarded as alternative integrated procurement strategies for clients to mitigate risks, minimize claims, integrate the diverse interests of a complex construction project, and offer incentives to provide value-added services. However, the adoption of GMP/TCC contracts may also generate significant risks and difficulties that merit considerable attention. This paper aims to provide a concise review of the potential pitfalls of the GMP/TCC scheme in general and identifies the key risk factors and potential difficulties associated with GMP/TCC in comparison with other procurement strategies in construction in particular via an empirical survey of clients, contractors, and consultants in Hong Kong. The survey data gleaned from 45 valid replies were analyzed using the mean score ranking technique, Kendall’s concordance test, and Spearman’s rank correlation test. The survey results indicated that “involvement of inexperienced or claim-conscious contractors in a project procured by a GMP/TCC contract” was considered to be the most significant risk factor; while “design development must keep pace with main contractor’s program for tendering the domestic subcontractors’ works packages” as the major difficulty in implementing GMP/TCC projects. The research findings derived from this study are particularly essential in assisting the contracting parties to mitigate the detriments brought about by potential risks or difficulties when embarking on GMP/TCC contracts. It has also generated valuable insights into developing effective recommendations for alleviating the barriers to GMP/TCC success for future construction projects.     

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.     

Owners Respond: Preferences for Task Performance, Delivery Systems, and Quality Management

Twenty years ago, public owners did almost all of their own design work and project inspection, but this is no longer the case. Innovative construction ideas of 15 years ago are now considered mainstream, and newer ideas are taking their places. Fifteen years ago, the concept of fast-track construction was still being researched and many federal agencies refused to fund it; today, most large federal projects call for some sort of fast tracking. These systems allow construction input into the design process of construction projects. Whoever performs tasks such as scope development, prebid cost estimates, and quality assurance can significantly affect the quality of the project, as can which delivery system is used. The Construction Institute of ASCE sponsored a survey of construction owners to determine what delivery systems are used in their projects and whom they select to perform various tasks. The survey also sought to ascertain the owners’ satisfaction level with the performance of the individuals and systems they choose. This paper, written for practitioners and researchers, describes the results of that survey.     

Single versus Multiple Prime Contracting

Policies regarding public building construction affect the interests of taxpayers, construction authorities, general contractors, specialty contractors, and other stakeholders. At the state level, the debate as to the optimal form such policies should take has become an ongoing struggle among competing interests. This study presents a systematic analysis of the main issues regarding single versus multiple prime contracting with the purpose of providing objective data to illuminate the debate. A statistical analysis of project bids and final costs from a national sample of state construction projects reveals that public construction projects organized with multiple prime contracts tend to have 5% less direct costs than projects using a single prime contractor. Moreover, approximately 80% of these savings are attributable to lower bid costs for multiple prime projects. The results of this study are in agreement with theoretical bidding models and efficient risk allocation models. Theoretical bidding models suggest that, in the absence of disruptions, multiple prime projects should have lower direct costs than single prime jobs. Efficient cost allocation models suggest that when specialty contractors do not bear the risks associated with the single prime contracting method (e.g., bid shopping and payment delays) they are willing to lower their bids, and forego the premium they would normally charge in response to such risks, as seems to be the case in multiple prime jobs.