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|Federal Highway Administration > Publications > Public Roads > Vol. 72 · No. 2 > Applying AQS In the Highway Industry|
Publication Number: FHWA-HRT-08-006
Applying AQS In the Highway Industry
by Alberto Miron, Richard B. Rogers, and Peter A. Kopac
The advanced quality system offers promise for improving pavement quality while helping agencies finish paving projects on time and within budget.
Today more than ever, given current financial and personnel constraints, transportation agencies face the challenges of doing more with less and delivering projects on time. To improve efficiency and cost effectiveness, many agencies are adopting alternative types of contract delivery mechanisms — such as quality assurance (QA) specifications, performance-related specifications (PRS), and warranties — that affect contractors' responsibilities and liabilities.
In this operating environment, an additional tool available to transportation agencies is the advanced quality system (AQS) approach, a total quality management approach that has been proven in other industries and focuses on quality as the top priority. In the highway industry, the target quality level is the one that provides the optimal balance between project cost and a satisfactory level of performance throughout a pavement's life cycle. To help the evolution to a systems approach, transportation agencies can rely on proven quality management methods and concepts that are applicable to all types of organizations, including those dealing with the delivery of highway projects.
"The main goal of any highway agency is to ensure that pavements will maintain an adequate level of performance throughout their designed life," says Brett Haggerty, transportation engineer with the Flexible Pavements Branch of the Texas Department of Transportation (TxDOT) and project director for Research Project 0-5496, Tracking the Performance of HMA Mixtures in Texas. "Hence, it becomes necessary to adopt a system that ensures an acceptable level of quality during the most vital [stages of a project]."
To ensure that contractors understand and meet (or exceed) the requirements contained in project specifications, quality must be managed systematically throughout the process from quality planning to quality control, to quality assurance, and to quality improvement. Further, according to the principles of quality management systems, the best way to manage quality is through a system that transforms inputs (requirements, that is to say, specifications) into outputs (products and services) through a chain of value-adding interrelated processes. For example, the design process relates strongly to the specification development and construction processes, and more cost-effective construction can be achieved when the assumed materials properties used in the design are also those specified and those the contractor targets during construction.
For transportation projects, "the use of quality systems is critical for tying together design, construction, and the resulting performance," says Linda Pierce, State pavement engineer for the Washington State Department of Transportation (WSDOT).
Toward that end, the Federal Highway Administration (FHWA) supports the innovative AQS approach, which could help State departments of transportation (DOTs) improve quality in highway paving projects. An AQS seeks early involvement of all stakeholders in an integrated quality management system that continuously improves its own processes and the quality of the product delivered.
FHWA introduced the AQS concept to highway professionals attending the Infrastructure Research and Technology Stakeholder Workshop held in 2002 in Chicago, IL. As documented in the FHWA report Infrastructure Research and Technology Stakeholder Workshop Summary Report: Workshop Proceedings (FHWA-RD-03-071), the sessions provided the opportunity to solicit input from stakeholders on raising the bar on research and technology, deployment, safety and performance, and extending the life of pavements.
According to the workshop proceedings, one innovation suggested at the workshop is an AQS approach, which could improve the quality of finished pavements by ensuring that contractors meet the specified quality and performance expectations established during project design. By helping guarantee that those specifications are met during construction and that project performance data are used by the planners and designers, an AQS approach provides a closed-loop system.
"It is not our agency's role to prescribe how a contractor performs quality control, but our agency does identify opportunities that might eliminate barriers to innovation," says Tom Harman, team leader for the Pavement and Materials Technical Service Team at the FHWA Resource Center in Baltimore, MD.
Acting on recommendations from the workshop participants, FHWA held a workshop titled Advanced Quality Systems in November 2006 in Alexandria, VA, to discuss quality. The objective of the workshop was to generate discussion about what constitutes an AQS and how to best advance the systems. Individuals from State DOTs, academia, government, and industry shared knowledge and discussed potential solutions for advancing highway construction specifications and establishing an AQS.
What Is an AQS?
During the workshop, attendees settled on a preliminary definition of an AQS and then expanded it to embrace principles outlined in ISO 9001:2000, the set of standardized requirements for a quality management system, maintained by the International Organization for Standardization (ISO). The workshop's expanded definition is as follows: An AQS is an integrated quality management system to fulfill the customer's expectations of pavement performance by making optimum use of the available tools and resources to continuously improve the system processes and the quality of the product delivered while fostering cooperative working relationships among all parties. FHWA used this definition to plan research to be undertaken under a task order-type research contract titled "Advanced Quality Systems."
"An AQS helps fulfill those expectations for pavement performance," adds Harman. "It creates an environment of reduced risk for both the transportation agency and the contractor by ensuring that quality levels are met."
Although FHWA will further refine the workshop's definition, the focus of FHWA's AQS is on the development and use of tools within the integrated system. It is the specific tools, after all, that will distinguish FHWA's concept of AQS from that of other total quality management systems. The tools include nondestructive, rapid test procedures and equipment; analytical evaluation procedures; software programs; guidance manuals; and training courses and workshops (see "Some FHWA-Developed AQS Tools" on page 26). Some of the needed tools have already been developed; others are under development. The development of certain tools (for example, nondestructive evaluation equipment) is a continuous process that will last many years. However, currently there are enough new or innovative tools that can positively impact quality such that FHWA can begin promoting them within an integrated system concept.
A description of an AQS, as it might eventually be recommended for application in pavement quality management, follows.
Customers. To various extents, State DOTs engage stakeholders in the planning phases of transportation projects, but an AQS can help ensure participation by all stakeholders from the beginning, bringing greater efficiency to the overall process. An AQS recognizes the different kinds of customers involved with or affected by a highway paving project: road users, who receive the end result of the product realization process (pavement, for example); internal customers, who take part in the product realization (DOT and contractor personnel); and interested parties or stakeholders (legislators, professional organizations, Federal agencies, State Governments, and more). All these customers have stakes in the end result, and transportation agencies take their requirements into account.
Agency. In an AQS, the transportation agency captures the requirements of all customers in the system and puts them in the form of specifications that communicate to the contractor the level of quality that the pavement's characteristics must have. The agency ensures that the requirements are congruent with the skills of the personnel constructing the pavement. Under an AQS approach, specifications are more comprehensive than is typical, and the agency periodically evaluates the effectiveness of its quality management system in achieving the product and the system's quality objectives, and maintains communication with customers and stakeholders.
Resources and Tools
Database. The construction-quality database is the most important decisionmaking tool within an AQS. The database is not a stand-alone tool but rather is made up of integrated databases (containing data on design, construction, quality testing, cost, condition surveys, and maintenance) with common referencing capabilities and wide accessibility to facilitate real-time monitoring of field operations.
Through this integrated database, a DOT can, for example, establish the targets and standard deviations needed to develop specifications, trace the costs associated with particular specifications, and verify or revise performance prediction equations. An agency also can use the database to conduct risk analyses for assessing warranty specifications and to evaluate the effectiveness of its AQS. In general, an agency with a well-designed database can perform these and other analyses to help make data-based decisions that gradually improve every AQS element or activity and thereby continuously improve quality.
Funds. Monetary resources are central to an AQS, as they constrain the scope of actions an agency can take for continuous improvement of the system. An AQS underscores the cost of pavement quality and reminds agency officials that they need to make decisions throughout a project's life cycle to ensure delivery of a cost-effective product.
Personnel. Transportation agency and contractor personnel are a key element of the system because through their skills they add value to the chain of processes and activities that lead to the final product.
Infrastructure. More than in standard approaches, an AQS emphasizes the importance of infrastructure — buildings, workspace and associated utilities, process equipment (both hardware and software), and supporting services such as transportation and communications. Modern equipment is key to precise and timely completion of projects, and to maximization of quality.
Top Management Commitment
In an AQS, top management identifies the customer requirements for the pavement, defines quality and system objectives and the organization's quality plan, reviews the effectiveness of the quality system, and assesses customer satisfaction. In addition, managers ensure that staff members from the agency and contractor take action to prevent nonconformities. They also define responsibilities and authorities, and the communication required throughout the product realization, monitoring, assessment, and improvement processes.
The transportation agency ensures that all personnel performing work that affects pavement quality are competent in terms of education, training, skills, and experience. More specifically, the agency educates in-house and contractor personnel about the relevance and importance of their activities and how they contribute to achieving quality. Agency officials maintain and use updated personnel records and evaluate the effectiveness of the various quality-related actions being taken. An AQS especially prizes expertise — and management's awareness of it — and the database is crucial here as it can indicate the personnel or training needed.
Further, the transportation agency determines and provides the infrastructure needed to achieve the pavement requirements. Under an AQS approach, the agency revisits and redefines the role of quality managers so they can, as in any manufacturing process, influence the production decisions without being constrained by workplace hierarchy. The agency ensures that inspectors on the jobsite know what to look for and how to interpret results to make the best decisions on pay adjustments, including pay decreases, and possible corrective actions. In an AQS, there is less need for a dispute resolution board.
Product realization involves all activities before the project starts up through final acceptance of the pavement.
Project planning. During this stage, the transportation agency defines general project requirements that reflect its policies and objectives. The agency might issue requests for proposals at this stage if design is to be a contractor responsibility. Ideally, the level of trust and partnership between the agency and industry are such that public-private partnerships are attractive and feasible.
The transportation agency also uses a formal risk assessment and allocation that ultimately will lead to aligning the entire project team with customer-oriented performance goals. Further, the governing specifications (QA, PRS, warranty) are determined and become part of the contract documents. In an AQS, the agency might employ database analysis tools not necessarily used in standard approaches — such as FHWA's PaveSpec, SpecRisk, and Prob.O.Prof (Probabilistic Optimization for Profit) — to help write rational, fair, and objective specifications.
Design. Either the transportation agency or the contractor carries out this activity according to project requirements. Management assigns responsibilities and coordinates the communication channels between the different groups involved in design.
Designers can perform their duties using several tools. Traditional pavement design software is abundant; however, performance-related design is the state of the art in an AQS. Accordingly, an agency that has an AQS uses mechanistic-empirical pavement design procedures on new construction, rehabilitation, and maintenance to the extent that the agency will incorporate actual construction test results into validated performance models to determine the contractor's pay adjustment for quality.
Because the design and associated drawings and specifications define what the transportation agency wants, they all need to be consistent. Especially important: The design assumptions used to specify the quality of constructed pavement and predict its performance must be consistent with the quality and performance requirements called for in the specifications.
Verification. The transportation agency or the contractor verifies the design inputs, outputs, and underlying assumptions, including their compliance with input requirements. This process currently is inconsistent, with mixed results, but an AQS can bring precision and consistency by careful verification, which includes performing alternative calculations, comparing new designs with similar proven ones, or undertaking tests and demonstrations. The agency identifies potential problems and proposes solutions. Validation — confirming soundness and thus indicating official sanction — might be part of this process in case the methods and assumptions used are new to the design review and verification team and/or have not been proved elsewhere. The transportation agency maintains records of reviews and verifications.
The designer can use several newly available tools for design verification as well. For instance, High Performance Concrete Paving (HIPERPAV®) software enables a designer (structural design or mix design) to estimate the effect that the design parameters will have on behavior of a pavement under certain environmental, construction, and materials conditions. The conditions become "What if?" scenarios that allow for design optimization.
Adjustment. The transportation agency or the contractor might recommend design changes as a result of design review and verification. Once the changes are made, the agency reviews, verifies, and validates them as appropriate and approves them before implementation. This review includes evaluation of the effect of the changes on the product already delivered (that is, pavement already laid). The agency maintains organized records of changes and any necessary actions. The AQS approach considers and more readily incorporates adjustments that benefit both parties, such as those that improve constructability without compromising performance.
Construction. During this stage, the transportation agency or a contractor performs the actual pavement construction, rehabilitation, or maintenance. A construction QA system is in place, and the level of detail of its related activities is defined depending on the type of governing specification (QA, PRS, warranty).
More than in current practices, AQS approaches use statistically sound and valid specifications that deliver the product quality and performance the DOT wants. Performance specifications (QA, PRS, warranty) are more common than method specifications in AQS approaches.
In an AQS, the agency or contractor pays close attention to detail in preconstruction planning and deployment of the paving operation, and the contractor deploys better equipment and more skilled labor as necessary to achieve the specified goals for quality. Ideally, equipment is mostly automated for highway construction operations, and the builder employs faster construction techniques to minimize traffic disruption.
Process control. Process control refers to the QA actions and considerations necessary to assess and adjust production and construction processes to control the level of quality in the pavement. In an AQS, this is a contractor activity since the contractor is the one capable of modifying its own processes.
Work instructions, use of suitable equipment, use of monitoring and measuring devices, implementation of monitoring and measurement, control of nonconforming product, and release (approval) of conforming product are contained in a quality control (QC) plan. As part of its QC process, the contractor identifies the product status in terms of monitoring, measurement, and acceptance. The controls and related responsibilities and authorities for dealing with nonconforming product are part of the QC plan.
In an AQS, the transportation agency aids in process control by defining criteria for review and approval of the processes, approval of equipment and qualification of personnel, use of specific methods and procedures when they apply, record-keeping protocols, and verification/validation procedures. In addition, during periodic construction quality audits, the agency ensures that any product that does not conform to requirements is identified and corrected to prevent its unintended use or delivery.
A number of tools are available for process control, including preprocess control, that enable contractors to plan their operations by simulating construction scenarios and their effects on pavement behavior. These tools include enhanced HIPERPAV, the Concrete Mixture Performance Analysis System (COMPASS), and Prob.O.Prof software. In an AQS, the contractor also uses statistical process control tools, and the contractor and the transportation agency, or an independent party (such as a commercial testing laboratory), use high-speed testing devices to measure quality continuously in the field in a timely fashion through nondestructive techniques, and the results of measurements are reported in real time.
Acceptance. This QA activity consists of sampling and testing, or inspection, to determine the degree of compliance with contract requirements. In QA and PRS projects, the transportation agency monitors and measures the quality characteristics of the pavement at appropriate stages of the product realization process to verify that requirements were met. If the contractor's test results are used for acceptance, the agency validates them by conducting its own tests (at a lesser frequency) and then performing statistical hypothesis tests (t-test to compare the means and f-test to compare the variances). In an AQS, validation becomes less and less necessary because the systems approach (which leads to improvements in quality-related activities such as construction equipment development, construction process control, and technician training) makes construction so precise that there is less need to measure and confirm project features.
"At least for pavements, knowing how the pavement was constructed — air voids, binder content, density, and so on — can provide insight on how the pavement performs, or for that matter, why it may not have performed as expected," says WSDOT's Pierce. "Having this knowledge provides an agency with the ability to make changes as needed to obtain the desirable quality level."
In warranty projects, DOT inspectors periodically determine payment after monitoring of the inservice pavement and at the end of the warranty period. Inspection consists of measuring compliance of the pavement with the condition indicators set in the contract requirements. During construction, the agency performs quality audits of the contractor's process control and quality management system, keeping records of the audits and data generated in case disputes arise.
In summary, the level of testing and degree of involvement by the transportation agency depend on the type of specification governing the contract. However, the agency's purpose is to provide minimal yet sufficient presence and oversight to record evidence of its commitment to quality.
Assessment and Improvement
Monitoring. This project phase extends to monitoring the quality management system. The transportation agency or contractor applies suitable methods for monitoring the specified characteristics of the product, including efforts to collect pavement management system (PMS) data, when applicable.
In an AQS approach, agencies use feedback loops from their PMSs to monitor performance. Feedback loops are not used optimally in typical projects today. Agency officials often assume, based on design, that a pavement will last 20 years, for example. But such assumptions are often wrong, and the information on the actual condition of a pavement does not get back to the personnel who need it, or to make specification adjustments affecting future projects.
The monitoring methods demonstrate that the processes and the pavement perform as planned. When expectations are not achieved, the agency or contractor takes corrective actions to ensure conformity. The transportation agency maintains records of conformity with the acceptance criteria.
Assessment. Using a feedback loop, an agency determines, collects, and analyzes data to demonstrate the suitability and effectiveness of its quality management system, and to evaluate where continual improvement of the system can be made. At least one potential objective method is available to assist agencies in determining the effectiveness of, and making improvements to, their quality management systems. This method currently is being refined, expanded, and improved/clarified under an FHWA research contract so that the method can have wider application. Other potential data analyses include surveys of customer satisfaction, evaluation of suppliers, and characteristics of and trends in the product realization processes, where opportunities for preventive action are identified.
Some FHWA-Developed AQS Tools
PP = project planning; D = design; V = design verification; Ad = design adjustment; C = construction; PC = construction process control; Ac = construction acceptance; M = monitoring; As = assessment; CI = continuous improvement; T = Training
On the product side, the transportation agency evaluates performance models and examines correlations among quality, cost, and performance to improve its construction specifications. Note that this process, as well as the previous one, addresses both the pavement and the agency's capability to deliver a quality product.
By conducting self-assessments, the transportation agency can review its activities and results systematically, thus identifying areas requiring improvement and determining priorities.
Continuous improvement. In an AQS, the agency continuously improves the effectiveness of the quality management system and its products through corrective and preventive actions and top management review. The agency takes action to eliminate the causes of nonconformities and prevent recurrence. The agency has procedures to review nonconformities (including customer complaints), determines the causes of nonconformities, evaluates the need for action to ensure that nonconformities do not recur, determines and implements actions needed, and reviews the corrective actions taken. In this manner, the foundation is set for systematic improvement in pavement performance that counts on specifications based on objective information and a commitment to exceeding customer expectations.
The Future of AQSs
New and evolving industry roles that come with adoption of innovative specifications and alternative project delivery methods are changing conventional practices employed by agencies to define, assess, and improve pavement quality. An AQS built on ISO 9000 principles can help a transportation agency maximize its resources within a comprehensive quality management plan that integrates value-adding activities to fulfill and raise customer expectations.
Probably the most important improvement an agency can make is to adopt a comprehensive, integrated construction-quality database that allows analysis of design, quality, time, cost, and performance. This kind of database can address funding constraints with analyses to establish the optimal target quality level — the level that provides the best balance between product performance and cost. Also, such a database can provide accurate feedback (both immediate and long term) so top managers and designers can make the necessary refinements in quality-related policies, objectives, and targets.
"Quality management programs make it possible to improve pavement performance and drastically reduce construction and rehabilitation costs," says TxDOT's Haggerty.
FHWA is working to expand these benefits across the Nation. For instance, the agency provides numerous software tools to assist DOTs and contractors with some of the activities that comprise an AQS. The agency already offers rapid, nondestructive testing procedures, such as the Magnetic Imaging Tools (MIT) Scan-2 dowel bar locator and the impact-echo device for measuring slab thickness, to improve process control and acceptance activities. More such developments and new applications of existing technologies are needed, and FHWA is active on these fronts. To assist DOTs in keeping up with new developments and assure proper implementation, FHWA has in recent years offered a number of courses and workshops that deal with individual aspects of AQS.
1. Quality Management Systems Requirements, ISO 9001 INTERNATIONAL STANDARD, 3rd ed., 2000-12-15.
2. Infrastructure Research and Technology Stakeholder Workshop Summary Report: Workshop Proceedings, Publication No. FHWA-RD-03-071, Federal Highway Administration, McLean, VA, September 2003. See www.fhwa.dot.gov/infrastructure/irtfinalsep03.cfm.
3. Advanced Quality Systems: Guidelines for Establishing and Maintaining Construction Quality Databases, Publication No. FHWA-HRT-07-019, Federal Highway Administration, McLean, VA, November 2006. See www.fhwa.dot.gov/pavement/concrete/pubs/07019/index.cfm.
4. Pathomvanich, S., et al. Procedure for Monitoring and Improving Effectiveness of Quality Assurance Specifications, Transportation Research Record No. 1813, Transportation Research Board, Washington, DC, 2002. See http://trb.metapress.com/content/u4884146720m3854.
Alberto Miron is a civil engineer currently managing bid design efforts for highway concession projects in North America for worldwide infrastructure developer Grupo Ferrovial. He previously worked for The Transtec Group, Inc., where he focused on concrete pavement quality and performance and conducted pavement design and assessment of toll road projects. His practical experience in quality management spans implementation of an ISO 9000 quality management system for El Salvador's highway trust fund, field experience that includes highway construction QC/QA, development of a quality database, and development of the first statistics-based pay adjustment factors for highway construction QA specifications in El Salvador.
Richard B. Rogers has been with The Transtec Group, Inc., since 2004. Prior to that, he worked for the Texas Department of Transportation for 25 years. He has performed a variety of supervisory and technical responsibilities in areas such as pavement design, management, and testing and evaluation; specification development; and data collection and analysis.
Peter A. Kopac is a senior research highway engineer on the Pavement Design and Performance Modeling Team in FHWA's Office of Infrastructure Research and Development. He has almost 40 years of highway-related experience, including 31 years with FHWA. His primary research focus has been on QA systems. He has assisted numerous agencies in developing, reviewing, and analyzing their QA programs. He is also an active member of the Transportation Research Board's Committee AFH20, Management of Quality Assurance.
For more information, contact Alberto Miron at 512-965-1872 or email@example.com, Richard B. Rogers at 512-451-6233 or firstname.lastname@example.org, or Peter A. Kopac at 202-493-3151 or email@example.com. For more on the FHWA research project on quality management systems, contact Peter A. Kopac.
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