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Publication Number: FHWA-HRT-12-027
Date: May 2012
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In early 2008, the Federal Highway Administration (FHWA) issued a task order under the Advanced Quality Systems Indefinite Delivery/Indefinite Quantity Contract for a contractor to quantify the effectiveness of State quality assurance (QA) programs. The objective of the study was to develop, apply, and make recommendations for the use of a procedure that transportation departments could use to quantify and improve the effectiveness of existing QA programs.
The goal of this study was to review and critically assess the procedure described in Transportation Research Record 1813 (TRR 1813) for monitoring and improving the effectiveness of construction QA programs. The scope of the study consisted of the following activities:
The first of five project tasks was to form a technical working panel of at least four representatives from State transportation departments. Four agencies were chosen to participate based on their knowledge and experience. An introductory project meeting was held in December 2008 to discuss the objectives and scope of the project with State representatives and to request their input. Each representative agreed to provide QA data from construction projects in their State for the team to analyze.
Following the meeting, the research team provided questionnaires requesting information about each agency’s specifications regarding the following three issues contained in the published procedure and discussed at the introductory meeting: (1) quality desired by the agency, (2) quality specified by the agency, and (3) quality received by the agency. The team followed up the questionnaire distribution with phone calls to obtain information not originally provided by the agency.
The research team received both PCC and HMA pavement QA specifications from each of the agencies. During review, it became obvious that a number of items the team anticipated analyzing were missing. For example, in order to analyze quality desired by the agency as originally proposed, it is necessary to know the acceptable and rejectable quality levels (AQLs and RQLs) for the quality characteristics specified. In almost every instance, this value was not known. Even with additional contact, it was apparent the agencies were unable to provide the information necessary, either because it did not exist or because extraordinary means (such as specially designed software) would be required to extract the data from agency records. With limited staff available in the agencies, the data were deemed unattainable, and the research plan was modified.
The team considered the additional possibility of extracting financial data from the agencies to estimate the overall performance of the QA program. It was found that these data were as much or more difficult to obtain as the originally sought data.
As an alternative approach, the team decided to analyze agencies’ QA programs using the details of the acceptance procedures contained in the construction specifications instead of using actual QA data. The detailed work plan for the project, specifically, the scope of subtask C.1 in the prospectus, was modified. The revised scope includes the use of software tools such as SPEKRISK and Probabilistic Optimization for Profit (Prob. O. Prof) where appropriate.
The remainder of this report documents the activities of the research team to analyze two PCC and two HMA pavement specifications to determine the effectiveness of agencies’ QA programs.
A procedure was developed to assist State highway agencies (SHAs) and FHWA in evaluating the effectiveness of construction QA programs. The procedure, described in TRR 1813, calls for data analysis of the State’s construction quality database to assess the effectiveness of the QA specification used by the Florida Department of Transportation (FDOT) for asphalt pavement construction. The procedure can be used to quantify the effectiveness of a QA program while identifying problem areas so they can be corrected. It also has the potential for use as a benchmarking tool for State highway agencies. The procedure was used to analyze FDOT’s Central Quality Reporting database and make recommendations to the State.
After analyzing FDOT’s database with the TRR 1813 procedure, some inconsistencies were found in the specifications in terms of communicating and receiving the desired quality level. In addition, it was concluded that even if the specification is perfect, it would not remain perfect for long because of advances in the construction industry. There will always be a need to monitor and make frequent adjustments to specifications.
Topics: research, infrastructure
Keywords: Quality assurance, Percent within limits, SPECRISK
TRT Terms: research, strategic planning