A reliability growth simulation test bed

This paper presents a reliability growth simulation test bed that is useful in examining the reliability growth of complex systems. It has many potential applications, including cost vs. reliability growth analyses and reliability growth program planning. The most significant application of the simulation though, is that it provides a method for examining the robustness of existing reliability growth models under varying assumptions and test conditions. The simulation allows for a user to more accurately model the test event, in that corrective action strategies and corrective action delay times and can be employed. Because these events tend to violate the assumptions of some models, two existing and widely used reliability growth models are examined under a variety of test conditions and assumptions. The simulated system reliabilities from the test bed are compared to the projections obtained from both the crow extended model and the AMSAA maturity projection model (AMPM). The results indicate that both models perform acceptably under test conditions that adhere to the assumptions of the models themselves. The performance of the crow-extended model tends to degrade rapidly as the assumptions are violated, more specifically when the classification of modes is altered in any way. The AMPM appears to be robust to varying test conditions due to its limited assumptions. Other issues do exist though involving the selection of the proper form of the estimator which could have a significant impact on the accuracy of its projections.