Design Build Research Articles

Applying system dynamics for outsourcing services in design-build projects

This study analysed a system dynamics model for outsourcing engineering services in a large and complex project organisational structure that is typically associated with design-build (DB) project delivery. A literature review indicated that most of the reviewed papers implied the project engineering resources were totally insourced or the authors were silent regarding any resources that were outsourced. Comprehensive sensitivity analysis of various model variables was performed, which indicates that the quality and productivity of the outsourced resources as well as the initial number of assigned experienced engineers significantly impacted the amount and timing of engineering work completion. Project outcomes were also impacted by varying the number of initial and changed engineering tasks. The decision to insource/outsource engineering work on DB projects may have significant cost and time impacts, which should be considered by decision makers.

Geotechnical Requirements in the Design–Build Selection Process

Geotechnical uncertainty is always high before a comprehensive site investigation is completed. In many design–build (DB) projects, the contract is awarded with the geotechnical investigation included as part of the required design deliverables. To ensure the necessary geotechnical design and construction quality, the agency must include appropriate factors in the best-value (BV) selection process. This paper describes an investigation of specific design–builder selection decisions involved in the procurement phase of a DB project and the ways in which the geotechnical requirements are incorporated into the selection decision in state departments of transportation (DOTs). The results are presented from the study of four independent sources of information, which were obtained through a review of the literature on geotechnical requirements in procurement documents, a survey of 42 state DOTs, a content analysis of procurement documents from 26 states, and the findings from 11 structured interviews with design–builders whose markets encompassed more than 30 states. The study results led to the conclusion that geotechnical designer qualifications and the experience of companies with geotechnical projects were key in achieving quality in DB projects. The weight of geotechnical factors in requests for qualifications and requests for proposals (RFPs) should be assigned proportionately with respect to the other factors that define DB project success. Experienced DOTs were seen to tailor the amount of geotechnical information that they included in the DB RFP to the specific requirements of a given project. Interactivity during the proposal preparation period offered an agency the opportunity to understand how competing design–builders perceived the geotechnical risk and to adjust the procurement plan accordingly. Alternative technical concepts also were presented as a viable approach to reduce perceived geotechnical risks.

Analysis of Owners Safety Management Approaches in Design-Build Projects

Other than mining and agriculture, construction jobsites are the most dangerous workplaces in the United States. However, owners and contractors remain primarily concerned with whether or not a project is completed within the scope of the contract, on schedule, and on budget (Rechenthin, 2004). With the emergence of the Design-Build (DB) delivery system as a prominent method in public projects, owners drafting requests for proposals (RFPs) are given a unique opportunity to place an emphasis on the importance of safety practices in the award of best value DB contracts. This study reviewed 115 RFPs to investigate the role of safety management in Design-Build RFPs. Out of the 115 RFPs reviewed, 62 RFPs mentioned safety. An in depth analysis of this 62 RFPs was performed to determine safety management approached in Design/Build projects. Results suggest that owners can include safety criteria in their RFPs which can be part of an overall risk management plan, particularly on projects with greater interface between the construction work zone and the general public. Additionally, if differential safety performance is not an evaluation criterion, it should not be referenced in the RFP and safety expectation beyond legal and regulatory standards should be clearly spelled out.

Critical Issues for Implementing DB Projects in Taiwan

Even though the design-build (DB) delivery method has become a popular construction project delivery method in many countries, it is relatively rare in Taiwan. This study investigates the problems and difficulties that Taiwanese owners may encounter during using DB delivery methods. Twenty six problems over the four key stages of the DB process were first identified based on previous studies and expert interviews. A questionnaire survey was then conducted to determine the most pressing problems for Taiwan. The results of statistical analyses show that Taiwanese owners face key problems at all stages of the DB delivery method, especially during the tender preparation and valuation stages. These findings can be used by Taiwanese owners for successfully executing DB projects.

Comparison of Cost and Time Performance of Design-Build and Design-Bid-Build Delivery Systems in Florida

The choice of construction delivery system is one of the most important decisions that a public highway agency will make with regard to a highway, bridge, or transit construction project. Although several research projects have been conducted on the subject of comparing costs and project duration, there has been no study that statistically analyzes these factors specifically for transportation projects, much less one that eliminates the largest variable of all: different public agencies. The objective of the research reported in this paper was to determine which of two delivery methods, design-bid-build (DBB) and design-build (DB), delivers highway and bridge construction projects at the lowest cost and in the shortest time period, and to back up the findings with a rigorous statistical analysis of the data. Data were taken from the databases of the Florida Department of Transportation (FDOT) and arithmetically and statistically compared through Levene’s test, the independent samples t-test, the Welch unequal variances t-test, and the Mann-Whitney U test. In fact, this paper’s unique contribution is its rigorous statistical analysis of data gathered directly from FDOT, comparing the performance of the two delivery systems in Florida over a finite period of time. In this comparison, DBB projects performed significantly better in terms of cost according to all statistical and arithmetic tests. DBB projects did not compare as favorably in terms of duration. Some tests showed a statistically insignificant advantage to the use of DB over DBB, whereas other tests showed no difference between the two. Other public agencies can replicate the research and determine whether the same findings hold true in their situation.

Impact of Risk on Design-Build Selection for Highway Design and Construction Projects

AbstractThe design-build (DB) project delivery method continues to grow as a viable alternative delivery method for highway projects. The primary reason for selecting DB delivery is to take advantage of the time savings inherent in the process. However, because of low levels of design at the time of contract awards, DB contracts often carry more risks and uncertainties than other contracts, which makes the decision to select DB delivery complex. Applying risk analysis strategies and tools to the delivery selection process will help decision makers evaluate and select the DB delivery method consistently and defensibly. This paper examines 39 generic risk factors related to the DB delivery selection process. These risks were identified through previous research and risk analysis workshops on transportation projects worth more than $10 billion. To explore how these risks impact DB delivery selection, a questionnaire was developed to collect data from a national cross section of professionals with an average ...

Early Contractor Design Involvement to Expedite Delivery of Emergency Highway Projects

Events such as Hurricanes Katrina and Irene and the sudden collapse of the I-35W bridge in Minnesota forced state departments of transportation (DOTs) to step into the public spotlight and implement expedited procurement procedures to restore vital links in the transportation network as the media scrutinized their work every night on the evening news. This paper presents the results of case studies from Florida, Maine, Minnesota, Missouri, New York, and Utah where the DOT brought the construction contractor into the design process as the primary means to expedite the delivery of emergency projects. The case studies include the use of design–bid–build, indefinite delivery and indefinite quantity (IDIQ), construction manager–general contractor (CMGC), and design–build (DB) contracts as mechanisms to gain substantive contractor input on materials, means, and methods during design. The paper concludes that completing the design is the first obstacle to surmount in emergency procurements and that the surest tool to expedite emergency project delivery is to design around immediately available materials, equipment, and proven accelerated construction methods—information that is best developed by the contractor that will eventually complete the construction. The paper recommends that agencies develop expedited procurement procedures for IDIQ, CMGC, and DB contracts before emergencies occur and furnishes case study information for specific methods used to streamline routine procurement procedures.

How Do Design‐Bid‐Build and Design‐Build Differ?

When a single source is responsible for design and construction of a project, the delivery method is termed design‐build (DB). A design‐builder has sole responsibility for a project's cost, schedule, quality, coordination, and control. That definition, however, fails to clearly convey the principal advantage of DB over traditional design‐bid‐build (DBB). This article provides some key questions to help you distinguish between DB and DBB and help you determine which is most advantageous for your utility.

Design-Build: How to Increase Its Usage and Its Impact on Architects and Contractors in Singapore

The purpose of this paper is to explore the ways to increase the usage of design-build (DB). The scope covers how project managers (local and foreign) can play a role in increasing DB usage in Singapore. It is found that owners would adopt DB if their requirements can be properly met. This is achieved by having clear and comprehensive bid documents, having sketch designs prepared by client appointed consultants, and engaging experienced DB contractors. Clients also need to engage project managers and consultant quantity surveyors to manage the DB projects, but the liability for design rests on DB contractors. Clients want DB contractors to provide warranty for fitness for purpose. The conclusion is that clients welcome the use of DB if some concrete steps are taken to make it meet their needs better. This study also concludes that consulting and contracting companies welcome DB, as this procurement method does not have a significantly negative impact on them.

Performance of Design-Build Projects in terms of Cost, Quality and Time: Views of Clients, Architects and Contractors in Singapore

One of the major problems in the construction industry is that of fragmentation. This hasled to an increased adoption of design-build (DB) as a procurement route in recent years.This move attempts to solve problems associated with the use of the traditional designbid-build method.The performance of DB projects is investigated under three aspects, namely quality, timeand cost. Results of the opinion survey concluded that contractors, architects and clientsagreed that DB projects perform well in these three areas. This confirms the inherent advantagesthat DB has to offer. It is concluded that DB is indeed a worthwhile procurementroute but the various participants must understand its structure and accept the changesinvolved.

Determining Optimal Proportion of Design in Design-Build Request for Proposals

The design-build (DB) system is a popular and effective delivery method of construction projects worldwide. After owners decide to procure their projects through the DB system, they may wish to determine the optimal proportion of design to be provided in the DB request for proposals (RFP), which serves as a solicitation for design-builders and describes the scope of work. However, this presents difficulties to DB owners and there is little, if any, systematic research in this area. This paper reports on an empirical study in the United States entailing both an online questionnaire survey and Delphi survey to identify and evaluate the factors influencing owners’ decisions in determining the proportion of design to include in DB RFPs. Eleven factors are identified, i.e., (1) clarity of project scope, (2) applicability of performance specifications, (3) desire for design innovation, (4) site constraints, (5) availability of competent design-builders, (6) project control requirements, (7) user group involvement level, (8) third-party requirements, (9) owner experience with DB, (10) project complexity, and (11) schedule constraints. A statistically significant agreement on the 11 factors was also obtained from the (mainly nonowner) Delphi experts. Although some of the experts hold different opinions on how these factors affect the proportion of design, these findings furnish various stakeholders with a better understanding of the delivery process of DB projects and the appropriate provision of project information in DB RFPs. Because the result is mainly industry opinion concerning the optimal proportion of design, in addition and for completeness future studies should be conducted to obtain a big picture of the optimal proportion of design by means of seeking owners’ inputs.

Fuzzy model for predicting project performance based on procurement experiences

Abstract This paper presents a data-clustering-based fuzzy model for predicting the performance of construction projects delivered through different procurement methods. To illustrate the model, a sample of 96 substation projects of an electric power company, delivered through the design–bid–build (DBB), design–build (DB), and turnkey (TK) methods, were used as training and testing data for model development and verification. Through a factor analysis, an initial set of 48 variables was reduced to nine inputs to the model for predicting eight performance metrics as outputs of the model. To establish the input–output relationships for each metric, Sugeno-type fuzzy inference systems were built, wherein the fuzzy rules were derived from selected projects as the estimated cluster centers in the training data. For the limited sample, zeroth-order systems built with hybrid training were found to outperform both first-order systems and stepwise regression models in prediction accuracy, while sensitivity analyses confirmed their robustness. As the data represents the company's procurement experiences of substation projects, the model may be regarded as a way of implementing organizational learning to improve procurement decision.

설계시공일괄방식 사업의 업무단계별 사업비용 리스크요인에 대한 영향도 평가 및 분석

최근 세계 건설시장에서의 발주방식은 빠른 속도로 변화하고 있으며, 이에 대한 건설 사업도 대형화 및 고난이도 공사가 증가하고 있다. 이러한 사업의 많은 부분이 설계시공일괄방식 사업으로 발주 되고 있으며, 공사금액기준으로 2009년 국내 조달청 발주공사의 약 40%를 일괄입찰방식(Design-Build)으로 발주를 하고 있다. 반면 설계시공일괄방식 사업의 증가로 그 중요성은 강조되지만, 사업수행자의 사업비용 관리차원에서 기대이상의 성과를 얻지 못하고 있는 실정이다. 그 이유는 사업방식의 특성상, 기본설계 이후 사업 수행계약이 체결되며, 관련 신기술 및 공법 적용에 대한 발주 검토 미흡과 설계과정에서의 불충분한 협의 등으로 사업비용(Cost) 증가에 대한 리스크가 상존하기 때문이다. 이를 해결하기 위해 사업수행 과정에서 사업비용의 증가 원인에 대한 요인을 찾고, 전체 사업 업무단계(Business Process)에서 리스크요인(Risk Factor)에 대한 우선순위 선정과 긴밀한 관리가 필요하다. 따라서 본 연구는 설계시공일괄방식 사업의 특성과 관련한 문제점을 근거로 사업비용에 대한 업무단계별 중요도를 분석하고, 사업수행자 측면의 업무단계별 사업비용 증가에 대한 리스크요인을 도출하여, 그에 대한 영향도(Impact assessment)를 FMEA(Failure Mode and Effect Analysis)기법을 통해 평가하였다. Recently, a delivery system has been rapidly changed in the global construction market. Also, construction projects are becoming bigger and more technology-intensive. A lot of projects have been delivered by Design-Build(DB) System; from the standpoint of cost, approximately 40% of delivered constructions by a Public Procurement Service were DB in 2009. Nevertheless, the achievement has not surpassed our expectations on management of the project cost. On the characteristic of DB, the reasons why that happens are that projects contract have been signed after the Design Development Stage; the insufficient review about new technology and up-to-date construction methods; a lack of discussion in process of design. Those reasons cause a risk of increasing Cost of the projects. In order to solve these problems, it is desirable to find Cost-increasing factors in promoting the projects and select on the order of priority for Risk-Factor with careful management. Therefore, this study analyzed the weight of each phase of the project on the authority of properties of DB project, and identified Risk-factors which is increasing the cost on the aspect of project management. Based on this analysis, the impact assessment of Risk-factor is evaluated through the Failure Mode and Effect Analysis(FMEA).

Profit-oriented Impact Analysis of Demand Management Strategy on Design-Build Firms Using System Dynamics

In the past, a strategic management of work demands has been increasingly challenged to design-build (DB) firms. Such a management is capable of providing sufficient profitable impact of a project on them. Total project profit is mainly related to actual resources, work completion time, amount of rework, and costs. The degree of recycling work packages in the DB project delivery system is used as a measure of the quality of the performed work. However, there are few models available to evaluate the impact of a demand management strategy on the DB firms and to predict its behavior. We propose a decision-making support model as an aid for assessing the amount of rework and for predicting project profit resulting in a convincible demand management strategy. This model is constructed by using a dynamic feedback approach that can analyze the problems arising in complex managerial systems. For the purpose of illustration, widely acceptable strategies were applied into the model to explore their impacts on the DB firms. The results indicate that the model is helpful for the managers in selecting the most appropriate demand management strategy for successfully achieving their objectives.

IDENTIFICATION OF SELECTION CRITERIA FOR OPERATIONAL VARIATIONS OF THE DESIGN-BUILD SYSTEM: A DELPHI STUDY IN CHINA / ATRANKOS KRITERIJŲ PROJEKTAVIMO IR STATYBOS SISTEMOS DARBINIAMS VARIANTAMS NUSTATYMAS: DELPHI TYRIMAS KINIJOJE

The design-build (DB) system has been demonstrated as an effective delivery method and has gained popularity worldwide. However it is observed that a number of operational variations of DB system have emerged since the last decade to cater for different client's requirements. After the client decides to procure his project through the DB system, he still has to choose an appropriate configuration to deliver their projects optimally. However, there is little research on the selection of DB operational variations. One of the main reasons for this is the lack of evaluation criteria for determining the appropriateness of each operational variation. To obtain such criteria, a three-round Delphi survey has been conducted with 20 construction experts in the People's Republic of China (PRC). Seven top selection criteria were identified. These are: (1) availability of competent design-builders; (2) client's capabilities; (3) project complexity; (4) client's control of project; (5) early commencement & short duration; (6) reduced responsibility or involvement; and (7) clearly defined end user's requirements. These selection criteria were found to have a statistically significant agreement. These findings may furnish various stakeholders, DB clients in particular, with better insight to understand and compare the different operational variations of the DB system. Santrauka Įrodyta, kad projektavimo ir statybos (P ir S) sistema – veiksmingas vykdymo metodas, tad ji išpopuliarėjo visame pasaulyje. Tačiau pastebėta, kad per pastarąjį dešimtmetį atsirado ne vienas darbinis P ir S sistemos variantas, tenkinantis skirtingus kliento poreikius. Klientui nutarus projekto paslaugas pirkti naudojant P ir S sistemą, jam vis tiek tenka pačiam pasirinkti tinkamą derinį, idant projektas vyktų optimaliai. Tačiau darbinių P ir S variantų pasirinkimas beveik nebuvo tyrinėtas. Viena pagrindinių priežasčių – trūksta vertinimo kriterijų, kurie leistų nustatyti kiekvieno darbinio varianto tinkamumą. Siekiant nustatyti tokius kriterijus, atliekant Delphi apklausą trimis etapais buvo apklausta 20 statybos ekspertų iš Kinijos Liaudies Respublikos (KLR). Nustatyti septyni svarbiausi atrankos kriterijai: 1) kompetentingų projektuotojų statytojų pasiūla; 2) kliento pajėgumai; 3) projekto sudėtingumas; 4) kiek klientas kontroliuoja projektą; 5) ankstyva pradžia ir nedidelė trukmė; 6) mažesnė atsakomybė arba dalyvavimas; 7) aiškiai nusakyti galutinio kliento reikalavimai. Nustatyta, kad susitarimas dėl šių atrankos kriterijų yra statistiškai reikšmingas. Įvairioms suinteresuotosioms grupėms, o ypač P ir S klientams, šios išvados gali padėti geriau suprasti įvairius darbinius P ir S sistemos variantus ir juos palyginti.

Comparison of Public–Private Partnerships and Traditional Procurement Methods in North American Highway Construction

The number of public–private partnership (P3) projects in North America has increased significantly since the early 1990s, as policy makers and transportation officials seek alternative methods to supplement traditional funding sources to finance and deliver projects. Scholars have compared the cost and schedule overruns of P3 projects against publicly funded projects in mature P3 markets in Europe, but not in the North American market. This paper begins filling that gap by comparing the cost- and schedule-overrun results of 12 completed large-scale (greater than ~US$90 million) P3 highway projects in North America with previous research studies reporting on large-scale design–bid–build (DBB) or design–build (DB) highway projects. P3 project performance data were collected through interviews with project executives, and then findings were used from previous studies of traditional projects for comparative benchmarking data. Research results indicate that the P3 sample cost overruns averaged 0.81% and schedule overruns averaged 20.30%, compared with 1.49% cost overruns and 11.04% schedule overruns for DB projects and 12.71% cost overruns and 4.34% schedule overruns for publicly financed large-scale DBB highway projects. With a relatively small universe of completed construction phase efforts to examine, it is premature to draw explicit conclusions, yet results reported in this study point to tighter control of highway construction costs and delivery schedules when projects are delivered by the P3 method. Findings from this study provide empirical evidence for various theoretical advantages and limitations of P3 projects, as well as serve as a reference tool to compare the appropriateness of different project delivery methods.

A Classification Framework for Design-Build Variants from an Operational Perspective

Design-build (DB) is a generic form of construction procurement, and, rather than simply representing a single system, it has evolved in practice into a variety of forms, each of which is similar to, and yet different from each other. Although the importance of selecting an appropriate DB variant has been widely accepted, difficulties occur in practice due to the multiplicity of terms and concepts used. What is needed is some kind of taxonomy or framework within which the individual variants can be placed and their relative attributes identified and understood. Through a comprehensive literature review and content analysis, this paper establishes a systematic classification framework for DB variants based on their operational attributes. In addition to providing much needed support for decision-making, this classification framework provides client/owners with perspectives to understand and examine different categories of DB variants from an operational perspective.

Analysis of Selection Criteria for Design-Builders through the Analysis of Requests for Proposal

Selecting an appropriate design-builder is critical to the success of design-build (DB) projects. The objective of this study is to identify selection criteria for design-builders and compare their relative importance by means of a robust content analysis of 94 requests for proposal (RFPs) for public DB projects. These DB projects had an aggregate contract value of over US$3.5 billion and were advertised between 2000 and 2010. This study summarized twenty-six selection criteria and classified them into ten categories, i.e., price, experience, technical approach, management approach, qualification, schedule, past performance, financial capability, responsiveness to the RFP, and legal status, in descending order of their relative importance. The results showed that although price still remains the most important selection category, its relative importance has declined significantly in the last decade. The categories of qualification, experience, and past performance, by contrast, have become more important to DB owners for selecting design-builders. Finally, it is found that the importance weighting of price in large projects is significantly higher than that in small projects. This study provides a useful reference for owners in selecting their preferred design-builders.

Delivering Sustainable, High-Performance Buildings: Influence of Project Delivery Methods on Integration and Project Outcomes

AbstractThe demand for sustainable buildings in the United States has risen because of accelerated depletion of natural resources, rising energy costs and green house gas emissions, and increased awareness of indoor environmental quality. Recently, this demand expanded from including only low energy strategies and products in buildings to prioritizing maximum energy conservation and occupant well being. All of these characteristics represent aspects of sustainable, high-performance buildings. Project delivery methods—e.g., design-build (DB) and design-bid-build (DBB)—can affect the level of team integration, which has been reported by the industry to result in optimal project outcomes and better value to the owner. However, there is a gap in the literature to examine the relationships among these results. This research studied how project delivery methods influence an owner’s ability to achieve its sustainability goals mediated through the level of integration achieved in the delivery process. The researc...

Determining the Appropriate Proportion of Owner-Provided Design in Design-Build Contracts: Content Analysis Approach

AbstractThe request for proposal (RFP) with the design-build (DB) procurement arrangement is a document in which an owner develops his requirements and conveys the project scope to DB contractors. Owners should provide an appropriate level of design in DB RFPs to adequately describe their requirements without compromising the prospects for innovation. This paper examines and compares the different levels of owner-provided design in DB RFPs by the content analysis of 84 requests for RFPs for public DB projects advertised between 2000 and 2010 with an aggregate contract value of over $5.4 billion. A statistical analysis was also conducted to explore the relationship between the proportion of owner-provided design and other project information, including project type, advertisement time, project size, contractor selection method, procurement process, and contract type. The results show that the majority (64.8%) of the RFPs provides less than 10% of the owner-provided design. The owner-provided design proport...