Assessing State Transportation Agency Constructability Implementation

Although guidance is available for state transportation agencies to establish constructability review processes (CRPs), nationwide implementation has been slow due, in part, to a lack of clarity regarding related costs and benefits and a perception that CRPs are resource intensive. This study funded by the National Cooperative Highway Research Program reveals that while numerous states have attempted implementation in various forms, obstacles have frequently either hindered or halted progress. Four elements appear to be essential for the successful implementation and continuance of a CRP: (1) institutionalization of the CRP Champion, (2) an emphasis on a quality-driven as opposed to a schedule-driven design process, (3) clear yet flexible guidelines for executing constructability reviews across the broad range of project types and sizes, and (4) a vehicle for meaningful expert input from construction contracting professionals. A benefit-cost model, founded on the proposition that CRP implementation provides efficiencies that result in significant cost and schedule reductions, is demonstrated using case studies. A need for more precise identification of costs and quantification of benefits is noted.     

Industrial Project Constructability Improvement

Constructability is defined as the ability of project conditions to enable the optimal utilization of construction resources. Constructability improvements may heighten the construction‐sensitivity of designs, render the communication of engineering information as more effective, optimize construction‐originated construction techniques, increase the effectiveness of construction management policies, improve vendor∕subcontractor services, or identify needs for designer‐constructor communication during the project. Constructability improvement ideas collected on a large refinery expansion project are analyzed for content, and classification frequencies are observed. Analysis of engineering rework exposes the causes and costs of rework that occurs as a result of constructability problems.     

Collecting Constructability Improvement Ideas

Project constructability improvement data collection techniques including voluntary survey, questionnaires, interviews, preconstruction meeting notes, and final project reports are discussed and analyzed in detail. Constructability data collected on a large refinery expansion project solicited with various collection techniques from various project personnel are presented. Considering six major types of constructability improvements, from both quantitative and qualitative points of view, two primary questions are addressed: (1) Which data collection methods are best in soliciting certain types of data; and (2) which source types are the most effective contributors in soliciting certain types of data? Numerous recommendations for effectively collecting constructability improvement data are presented.     

Constructability Practices to Manage Sustainable Building Knowledge

Construction professionals have knowledge and competencies that can help improve the design and delivery of sustainable buildings. The introduction of construction knowledge during design using constructability practices has been shown to improve design and project performance. From a process perspective, this paper examines specific constructability techniques that can help manage sustainable building knowledge throughout the design process. Through scientific research, four constructability practices employed at the Pentagon renovation are assessed for their capability at managing sustainability input from contractors. The four practices are: (1) the use of an integrated organizational team to champion the effort; (2) physical and computer building models (mock-ups); (3) on-board reviews; and (4) lessons learned workshops. Twenty-one specific principles are then identified to provide further guidance to industry practitioners. These practices and principles pinpoint methods to help manage sustainable building knowledge, especially that made available by construction professionals during design and construction.     

Tolerance and Constructability of Soldier Piles in Slurry Walls

Process capability (PC) characterizes the variation in a parameter of a process’s output. From a constructability perspective, investigating PCs for geometric variation is important when specifying tolerances for all construction processes. This paper investigates a case involving soldier piles used in a slurry wall and compares the design specified tolerances to as-built field data. As with other cases investigated by the writers covering many major construction processes, this case also shows that designers specify tolerances based on tacit estimates of variation limits, not PCs. Consequently, the PCs consistently exceed the design specified tolerances, preventing the possibility of proper tolerance management and causing problems to manifest during construction. The writers conclude that variation estimates are an inaccurate basis for specifying tolerances and instead should be based on PCs.     

Constructability Concepts in West Port Highway in Malaysia

This paper presents a case study of the applications and nonapplications of constructability concepts to illustrate, in a practical way, the impact that these concepts can have on a project’s success. This case study, which conveys an important message with regard to the application of constructability concepts, was purposely chosen from among prestigious projects in peninsular Malaysia. The basic message, as viewed by the interviewees, is that applying these constructability concepts will enhance a project’s constructability, consequently optimizing the schedule, cost, and quality of the project for the benefit of all the parties involved. The interviewees for the case study agreed that the applied constructability concepts were derived from their own experience and not based on any existing formal program. The absence of a systematic technique for transferring construction experience and knowledge to all the participants in all phases of a construction project is the reason behind the lack of constructability in our construction industry today.     

Organizing Constructability Knowledge for Design

Construction contractors have significant constructability expertise to contribute to the design process of projects. To utilize this expertise most effectively, the right information must be made available to the design team at the proper point in time and at the appropriate level of detail. Current methods for utilizing construction knowledge in design have made significant advances to improving projects. However, they are typically rudimentary: unstructured, not very efficient, and rely heavily on reviews. Organizing constructability information according to its use in the design process will allow project teams to take the best advantage of the construction expertise. This paper introduces a model for organizing constructability information based on timing and levels of detail. The model differs from current approaches because of this focus. How the model was developed is described. It is tested on six case study projects to assess applicability on different projects. An illustrative example is provided using a detailed case study of the Pentagon renovation project to show how the model can be used as a metric to guide constructability input during design.     

Constructability Analysis in the Design Firm

The timely execution of a construction project is very important to the owner, who makes plans and commitments on the basis of the project’s anticipated completion date. Failure of design professionals to consider how a builder will implement the design can result in scheduling problems, delays, and disputes during the construction process. Constructability of design is a subjective scale that depends basically on a number of interdependent project-related factors. Many design firms have a formal (explicit) constructability program that is launched as early as the conceptual planning stage of the project. This research examines design professionals’ efforts to pursue constructability and provides recommendations for performing constructability reviews in an efficient and effective manner.     

Modeling of Functional Construction Requirements for Constructability Analysis

Evaluating construction requirements should be an indispensable part of improving the constructability of a facility project. However, a number of existing function analysis approaches focus mainly on the final functions with respect to the finished facility. The construction industry still lacks methodologies to represent and evaluate the functional construction requirements for constructability analysis. This paper develops the concept of intermediate functions for representing the construction requirements from three perspectives, namely, function user, function provider, and the temporal and spatial relationships between the user and the provider. This is followed by the development of an in-progress product model to abstract the construction lifecycle of a facility product utilizing the concept of component state. Furthermore, the reference relationships among such perspectives as in-progress product, intermediate function, resource, and process are addressed. Based on these reference relationships, the bottleneck states for providing the intermediate functions can be detected. A case study of constructing the deck of a bridge using the balanced cantilever approach is presented to illustrate the utilization of this concept and representation.     

Framework of Success Criteria for Design/Build Projects

Success has always been the ultimate goal of every activity, and a construction project is no exception. Due to the ambiguous definition of project success and the different perceptions of participants toward this concept, it may be difficult to tell whether a project is successful as there is a lack of consensus. Time, cost, and quality have long been the success criteria used to evaluate the performance of a construction project. However, such a list has been criticized as not being comprehensive. Even studies of the project success of a particular construction method, such as the design/build procurement system, are lacking in most previous research considering construction projects in general. This paper sets out to establish criteria for project success for a design/build project in construction, first by identifying relevant measures of project success for a construction project in past studies, with particular emphasis on design/build projects, and then by establishing a comprehensive assessment framework for project success for design/build projects. The significant impacts on the construction field of study, in terms of educational value and practical use, are also presented. With little research in the project success of design/build projects, the writers suggest a research focus for the study.     

Communicating Design Quality Requirements for Public Sector Design/Build Projects

This paper reports the results of a research study focused on how public sector owners articulated the requirements for design quality management in design/build (DB) projects. The research used the content analysis of 75 DB requests for proposals located in 35 states with an aggregate contract value of over $700 million with the mean price per project at roughly $15 million. The projects came from seven federal agencies as well as several state agencies. It found public owners are not availing themselves of the opportunity to evaluate design-builder design quality management plans and are primarily relying on the qualifications evaluation process to ensure design quality requirements will be met. Additionally, virtually all of the public owners in the sample neglected to require constructability reviews as a design quality management requirement in spite of the published benefits of this type of review. Finally, the paper concludes this area is one where a great deal of improvement for practitioners remains and the reason for a lack of focus on design quality in DB projects is due to a failure to shift the owner’s procurement culture from traditional project delivery to DB.     

Constructability Concepts in Kuala Selangor Cable-Stayed Bridge in Malaysia

The writers formulated a case study of the Kuala Selangor Cable Stayed Bridge to examine the application of the constructability concepts particularly during the conceptual planning and the design phases of the project. This paper presents the advantages of implementing the constructability concepts and the barriers that were encountered when applying these concepts during the planning and design phases of the cable stayed bridge project of Kuala Selangor in Malaysia. The writers concluded that barriers to constructability implementation that are related to the owner were the major impediments in the application of constructability concepts during the early conceptual planning phase. The opinion of the engineer was another factor behind nonapplication of some other concepts. At the same time, many others were implemented due to the awareness and opinion of the engineer and his ability to control their application.     

Impacts of Constructability Improvement

An analysis of the construction resource utilization tradeoffs, which occur from constructability improvements, provides insight into the constructability improvement process. Matrices of construction and engineering impacts likely to result from constructability improvements are presented. Constructability improvements collected on a large industrial construction project are analyzed for their impact to the job. Frequencies of occurrence of both desirable and undesirable impacts are noted, as are the cost‐significances of the various impact types. Constructability strategies and methods for achieving the most cost‐beneficial impacts are presented. Numerous findings are presented, such as the following: (1) The likelihood of delays may be decreased most effectively by increasing engineering information availability and understandability; (2) the amount of required construction manpower may be most effectively decreased by simplifying the design, combining design elements, and seeking optimal design‐originated construction techniques such as optimal construction systems, modularization, and improved design details. Of course, additional engineering effort may be required; and (3) construction activity durations may also be most effectively decreased by seeking optimal design‐originated construction techniques.     

Design/Build for Water/Wastewater Facilities: State of the Industry Survey and Three Case Studies

Documented successes of innovative delivery methods and recent changes in procurement laws are enabling water and wastewater utility owners to use alternative delivery methods for the construction of new facilities and the expansion of existing facilities. This shift toward alternative project delivery systems, such as design/build, has resulted in demand for additional guidance for owners and practitioners. This paper provides the results of an industrywide survey and three in-depth case studies. The survey results indicate large-scale growth in the use of design/build project delivery for water and wastewater facilities throughout the United States. The findings from the case studies indicate that common practices exist with regard to selecting a delivery system, contracting, allocating risk, evaluating proposals, determining the level of design in the request for proposals, using consultants, establishing trust, identifying key players, and permitting. These results serve as best practices for owners and practitioners using design/build delivery for the first time.     

Sources of Changes in Design–Build Contracts for a Governmental Owner

In recent years, many U.S. federal, state, and local governments have been authorized to use the design–build method of project delivery instead of the traditional design–bid–build method. Recent studies have not been definitive on the cost advantage of design–build for governmental owners. There are fewer change orders in design–build due to design errors because the designer (architect/engineer) and contractor are one entity, but there are other causes of change orders. Some literature suggests that changes requested by the owner of the facility are greater with the design–build method. This research examines the causes for construction-phase changes in 14 design–build and 20 design–bid–build projects. Total changes, expressed as number per contract, cost per contract, or percentage of original contract, were significantly lower in design–build. Fewer design errors in design–build accounted for this advantage. The number of owner-requested changes was significantly greater in design–build. The cost of owner-requested changes, averaged over all the projects, was significantly less for design–bid–build. The differences in changes due to differing site conditions were not significant. The concept that there are more owner-requested changes in design–build projects is supported by this research.     

Constructability Practices among Construction Contractors in Indonesia

The concept of constructability in the United States or buildability in the United Kingdom emerged in the late 1970s, which evolved from studies into how improvement can be achieved to increase cost efficiency and quality in the construction industry. It is an approach that links the design and construction processes. The studies in the Unites States, United Kingdom, and Australia have demonstrated that improved constructability has lead to significant savings in both cost and time required for completing construction projects. However, in implementing constructability improvement, it is important to consider the uniqueness of the construction industry in a specific country. This paper presents the study performed on the construction contractors in Indonesia with regard to their current constructability practices and its impact on the project performance. The study shows that many contractors in Indonesia have been implementing part of the constructability concept in their projects. The concepts that usually applied during the construction stage as part of the overall construction plan were planning the sequence of field tasks and analyzing layout, access, and temporary facilities     

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.     

Building Better: Technical Support for Construction

Increasing complexity of many constructed facilities and escalating demands for project performance are driving significant changes in design and construction. Increased project integration and technical support of construction operations provide a promising response to these demands. This paper identifies and describes nine critical activities to increase technical support for construction: integrate early planning; plan for regulatory compliance; consider construction methods and sequences in design; tailor and time technical information to users’ needs; provide materials to support effective construction; identify and provide construction-applied resources; create an environment for safe, productive, and high quality work; technically support efficient construction operations and completion; and transfer experience between projects. The paper’s relevance to industry practitioners includes multiple benefits of completing these activities for firms, projects, and professionals, along with the necessary steps to develop this capability and gain these benefits. Educators and researchers can use the activities to structure course topics related to technical fundamentals of construction and integration with design, along with future investigations of construction process knowledge.     

Constructability Rankings of Construction Systems Based on the Analytical Hierarchy Process

This paper uses the quantitative decision-making technique, the analytical hierarchy process, to derive prioritized scales for (1) the constructability factors; and (2) the relative contribution of common construction systems in a building superstructure comprising structural frames, slabs, envelopes, roof, and internal walls toward constructability. The identified constructability factors show that to enhance constructability design requirements should be easily visualized and coordinated by site staff, while designs should allow economic use of contractors’ resources and enable contractors to develop and adopt alternative construction details. The precast method is rated as the most constructible construction method, indicating its better performance in facilitating efficient and safe construction in the busy urban environment in Hong Kong. However, the methodology adopted in this study should be of international interest, especially for those desirous of improving constructability of designs with different contextual backgrounds.     

Constructability Analysis of the Bridge Superstructure Rotation Construction Method in China

Constructability analysis can provide valuable input to optimizing urban bridge construction in terms of reducing impacts on traffic, safety, and overall project budget and duration. This paper presents a constructability analysis of the superstructure rotation method for bridge construction. The method includes building the bridge parallel to the obstacle being overpassed (a river or a highway) and then rotating the superstructure into place. The method has been used successfully in over one-hundred bridges (mostly in China). The paper documents two case studies of bridges that used this method and provides an analysis of the constructability of the method. This includes identification of the factors influencing the constructability of the methods and lists of design and construction objectives/strategies that support the constructability of bridges using this method.