Sponsor:

Air Force Research Laboratory

Research Team:

C. Richard Cassady, Jason Stout, Jeff Rieske, Yisha Xiang, Edward A. Pohl, Scott J. Mason, Thomas Yeung, Kellie Schneider , Chase E. Rainwater

Universities Involved:

University of Arkansas

Start Date:

09/05/03

End Date:

01/29/05

Summary:

This project develops a multi-state maintenance models to address the following issues: *Dependence of military organizations on the reliability performance of repairable systems
*Limitations of existing resources required to perform maintenance actions
*Limitation of existing research in multi-state selective maintenance
All military organizations depend on the reliable performance of repairable systems for the successful completion of missions. The use of mathematical modeling for the purpose of modeling repairable systems and designing optimal maintenance policies for these systems has received an extensive amount of attention in the literature. Unfortunately, the vast majority of this work ignores potential limitations on the resources required to perform maintenance actions. This shortcoming has motivated the development of models for selective maintenance, the process of identifying the subset of actions to perform from a set of desirable maintenance actions. Previously, we have developed a class of mathematical models that can be used to identify selective maintenance decisions for the following scenario – A system has just completed a mission and will begin its next mission soon. Maintenance cannot be performed during missions, therefore the decision-maker must decide which components to maintain prior to the next mission. The selective maintenance models formulated to date are based on the assumption of binary (functioning, failed) component, subsystem and system status. As a result, mission reliability is used as the objective function in the resulting mathematical programming models. We wish to improve upon this approach in two ways. First, it may be more realistic to classify component status using more than two discrete levels (if not some continuous measure). This implies multi-state measures of subsystem and system status as well. Second, the performance of a military system typically can be measured using several measures in addition to mission reliability. All these performance measures are functions of the status of the components. The primary objective of this project is to develop multi-state selective maintenance models that incorporate multi-state component status and multiple measures of system performance.