Document Detail

Title: SD-83 - Benefits and Costs of Constructability: Four Case Studies
Publication Date: 10/1/1992
Product Type: Source Document
Status: Reference
Pages: 125
Russell, Gugel, Radtke, Univ. of Wisconsin-Madison
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Abstract

Construction industry participants are becoming increasingly aware of the important benefits that constructability implementation can contribute to their projects. Recent research has identified different approaches owners use to provide constructability input to their projects. This technical report provides a comparative analysis of three such approaches studied in four case studies. The relative attributes of each approach are described. For each approach, the quantitative and qualitative benefits accrued through constructability implementation are also presented. In addition the cost associated with each approach is presented in both a quantitative and qualitative manner. A comparison of benefits and costs attributed to each approach is provided. Finally, the practical implications of the three approaches are described in terms of relative applicability, relative benefits-costs and performance implications, and steps taken by each respective owner to facilitate constructability.

Research Methodology

The research effort consisted of three phases: (1) questionnaire survey, (2) personal interviews, and (3) case studies. In Phase I, the researchers mailed a six-page questionnaire survey to 1,591 organizations in the U.S. construction industry. A total of 263 usable responses were received, representing a 16% response rate. In Phase II, the researchers met with 83 industry professionals while conducting interviews with 62 different organizations.

Phases I and II were used to identify four case studies aimed at providing benefit/cost data associated with implementing constructability. Phase III involved data collection and analysis for each of these case Studies. The four case studies included completed projects involving one commercial office building development, one consumer products manufacturing facility, and two petrochemical projects. Data was collected by means of extended personal interviews. Documentation of each of the four case studies is provided in Appendices A through D.

Observed Constructability Approaches

Among the four case studies, researchers observed three different approaches to constructability. Each varies by level of formalization, resources required, and long-term benefit accrued through documenting lessons learned.

Case study 1, the commercial office building development, identified constructability input as a service provided by either a constructor or construction management firm during project activities prior to the start of construction. This approach is referred to as constructability services. This approach often combines the benefits and costs of constructability with other services provided such as value engineering and project planning and thus is not well defined. The services are primarily required to supplement an owner’s limited resources for early planning and design evaluation.

Case study 2, the manufacturing facility, identified a project-level program that obtains construction input during pre-detailed design activities. This approach was termed specialized formal constructability program. Construction personnel assist the owner in establishing the philosophy, procedures, and tracking systems that comprise the program. However, application of this approach is typically limited to selected projects. Consequently, formal corporate-level tracking of lessons learned and benefit/cost data resulting from constructability implementation are not routinely performed.

Case Studies 3 and 4, the petrochemical facilities, used a comprehensive tracking approach. First, corporate commitment, philosophy, and procedures related to constructability were captured within a corporate implementation manual. Second, lessons learned on each project were documented and entered into a corporate lessons learned file for reference on future projects. Savings and costs attributed to constructability were also recorded. In case study 3, the project management designated three constructability coordinators from the constructor’s organization. In case study four, the owner provided a corporate constructability coordinator that served as the coordinator on multiple projects concurrently.

Benefit, Cost, and Performance Implications

A qualitative description of benefits that were considered partially attributable to constructability services provided in case study 1, demonstrated reductions in total project cost and schedule that resulted from early construction input. The specialized-formal program implemented on case study 2 achieved a documented reduction in total project cost of 1.1%. The comprehensive tracking approach used to implement constructability on case study 3, was instrumental in achieving the desired schedule performance for the project. Due to the relatively large size of the project, the owner secured an experienced constructor that successfully applied their corporate lessons learned and reduced the total project cost by 1.1%. The constructor collected new lessons learned and tracked constructability benefits and costs to further monitor their corporate constructability program’s maturity. Finally, the owner-performed program implemented on case study 4, achieved a 10.7% reduction in total project cost, added 32 new constructability ideas to the corporate lessons-learned database, and established a benchmark to measure the organization’s program maturity.

Estimates of program cost between the two larger projects, case Studies 2 and 3, were of similar magnitude. Cost estimates associated with the comprehensive tracking approach as a percent of total project cost, however, varied by a multiple of 10. However, cost as measured through effort-hours expended on constructability as a percent of total construction field effort hours, appeared consistent between the two cases.

Although the approach selected in each case study was the most suitable for its given circumstances, each achieved different performance results. The constructability services approach provided the owner with a facility that met all project objectives. However, constructability obtained through constructability services, as opposed to other approaches presented, is more a byproduct of early construction involvement rather than an intentional attempt to avoid unnecessary construction difficulties. As a result, this approach tends to be informal and often neglects tracking lessons learned, or measuring benefits and costs to monitor its maturity.

The specialized-formal program approach also provided the owner with the desired facility while also meeting the established project objectives. The program was implemented by a seven member core constructability team that included a designated constructability coordinator. Lessons learned were captured and utilized through individuals that had extensive experience on previous owner projects through an existing partnering agreement between the two organizations. In addition, constructability costs and benefits were tracked to monitor the program’s effectiveness.

Finally, of the case studies implementing the comprehensive tracking approach, each used designated constructability coordinators to develop, implement, and monitor their constructability program. In addition, each case used corporate databases to track benefits and costs, as well as lessons learned across projects. By establishing databases, it is believed that the program initially experiences a large incremental increases in total-annual documented savings. However, as the program matures, and the design and construction processes are optimized, the program’s incremental increase in total-annual documented savings reach a steady-state condition. In the “mature” state, additional documented constructability savings are realized through application of new construction methods and technologies.

Steps to Facilitate Constructability

The first step that an owner should consider in implementing constructability, is to assess their characteristics and capabilities as well as the project’s characteristics. This enables the owner to determine the most appropriate approach to implement constructability. The four case studies outlined, applied three approaches to constructability. Each case, however, used a different project participant to implement constructability; a construction management firm, a partnered design/construct firm, an experienced constructor, and the owner’s own in-house corporate expertise.

In conclusion, each of these case studies displayed a unique approach to implementing constructability. The selection of each approach reflected both owner and project characteristics. Each approach, although different, used construction knowledge and experience to achieve project objectives.