ABSTRACT
Recently, state agencies have been successfully implementing construction manager/general contractor (CM/GC) delivery on highway projects. While early work packaging is frequently cited in the literature as a primary benefit of CM/GC, there is limited to substantiate or refute these benefits. Additionally, agencies need a better understanding of the current state-of-practice of early work packing in CM/GC to help with effective implementation.
In an ongoing Federal Highway Agency research project, 12 of 34 completed CM/GC projects reported the use early work packaging, and will be the focus of this study. Research methods used within this paper include: literature review, content review of agency manuals/instructions, project surveys, agency interviews, and case studies. Triangulated findings suggest that early work packaging can contribute to expediting project completion, mitigating project risks, reducing project cost, and minimizing public impacts.
To achieve these outcomes, agencies must perform detailed planning to generate severable/independent packages that take into account all potential impacts to the project. Trends in data indicate that early work packages can lead to cost savings, yet the sample size does not provide statistical significance. Future research should explore the performance of a larger data set of CM/GC projects with and without early work packaging along with a cost/benefit analysis of early work packages.
INTRODUCTION AND MOTIVATION
Figure 1. CM/GC Project Progression With and Without Early work packaging.
One benefit for agencies pursuing CM/GC is the ability to package work and allow for early release for construction as they are completed. When an agency decides to release an early work package, the process is very similar to the CM/GC process as a whole: a design package is developed, scope documents are created, a GMP is reached, and a contractor is given the notice to proceed.
Figure 1 compares a project performed with and without early work packaging. An early work package can consist of, for example, procuring materials to constructing early project tasks. As seen in Figure 1, Design Package 2 continues to develop while Design Package 1 is being completed and negotiated. Subsequent work packages follow the same process. As a result, overlapping of design and construction can accelerate project completion.
RESEARCH OBJECTIVE AND METHODS
The objective of this paper is to explore early work packaging in CM/GC projects, presenting the current state-of-practice of CM/GC early work packaging. The data for this study is derived from an ongoing FHWA research project which includes 34 CM/GC U.S. highway projects completed between 2004 and 2015, representing over 66% of the federally funded CM/GC projects during this time period. Of these 34 projects, 12 reported the use of early work packaging. With an understanding that there are few projects available, this research broadly explores the following questions:
a. What are the benefits gained from CM/GC early work packages and are they value adding?
b. What are the best practices for implementing CM/GC early work packages?
c. What future research is needed in the area of CM/GC early work packages?
To address these 1 research questions, a multi-method research approach was used to triangulate results. The approach includes: [1] a review of current literature; [2] a content review of agency manuals/instructions; [3] a performance survey of projects with early work packages; [4] interviews with agencies experienced with CM/GC; and [5] case studies of CM/GC projects.
RESULTS: WHAT WE LEARNED
Table 4 provides a summary of the results with a column showing which research methods support each result. The five research methods are shown, along with the sample size of each research method, and the number of times each result is referenced in these samples.
For example, “Expedite project completion” was found as cited in 12 of the 18 literature documents, three of the five agency policies, responded as a reason for packaging in 10 of the 12 survey responses, stated in all six interviews, and found as a reason for use in all three case studies. Using a multi-method research approach allowed the authors to triangulate the results and rank the findings by order of importance, as shown in the table.
DISCUSSION OF EARLY WORK PACKAGING IMPACT ON PERFORMANCE
Expediting project completion is the most commonly cited benefit of early work packaging in the literature (2,3,5,7,9,11-14,16,17,19,20,23,24). Likewise, the surveys indicated 22 of the 23 early work packages were motivated by project schedule acceleration either through procuring long12 lead items, overlapping design and construction, and/or preparation work. All agency representatives interviewed stated schedule acceleration as a benefit to early work packaging.
Finally, all three case studies found the projects used and benefited from early work packaging’s schedule acceleration. All five research methods applied in this study corroborated that accelerated project completion is the most common benefit of early work packaging. As stated by one agency representative, “putting work out that will accelerate the main core of work is always why we do extra packages.” This quote exemplifies acceleration being heavily valued, but as seen in Table 1, there are other benefits gained from early work packaging.
DISCUSSION OF CRITICAL IMPLEMENTATION FACTORS FOR EARLY WORK PACKAGING
Severability is stated as a requirement in all CM/GC manuals that discuss early work packaging is noted within the NCHRP 10-85 report as a quality of work packages. Of the five projects that addressed best practices within the survey, two responded that packages must be severable. As seen in project #1, if packages are not severable, the owner loses negotiating power and may risk cost growth or scope reduction. Alternatively, projects #2 and #3 claim severability as a reason for their success.
CONCLUSIONS
This study explores the use of early work packaging in CM/GC transportation projects through: reviewing the literature; reviewing agency manuals/instructions; surveying 18 projects; interviewing six agency representatives; and conducting three project case studies. This research contributes to the current body of knowledge by providing triangulated findings through a multi6 method approach that supports early work packaging’s potential to improve project performance. Research results point to these potential benefits of early work packaging: expediting project schedule; mitigating risks; reducing project costs; minimizing impacts to public; and matching funds.
These goals are obtained by creating work packages which: procure long lead items and/or volatile priced items; overlap design and construction; perform early work including right-of-way, utility, subsurface, and/or general prep work; and avoid environmental restrictions or disadvantageous seasons. Critical implementation factors include: maintain severability; proactive planning; involve contractor and stakeholders; and use after CM/GC experience is gained. In particular, severability is pivotal to creating early work packaging that does not diminish agency negotiating power, and risk cost and schedule growth.
The CM/GC projects with early work packages in this study showed a trend toward controlling project cost growth. Moreover, two of the three case studies support this finding with one-year schedule acceleration due to early work packages; and the third case study with 12% cost savings. Five of the six agency representatives interviewed also stated projects with early work packaging experienced added value often exceeding project goals.
The small sample size in this study limits statistical analyses; however, a triangulated approach ameliorated this shortcoming. Future research should compare the cost and schedule performance of CM/GC projects with and without work packages. As CM/GC matures in highway projects, a larger database of projects can be studied to provide empirical results.
Source: Iowa State University
Authors: Douglas Alleman | Dean Papajohn | Douglas D. Gransberg