Optimal allocation of reliability tasks to mitigate faults during system development

This paper considers reliability planning for a concept design for a new system where a portfolio of possible reliability development tasks exists; the goal is to find a selection and sequence of tasks to achieve reliability targets subject to time constraints at minimal cost. This is non-trivial given that each task potentially can expose several different weaknesses and each weakness potentially can be exposed by several different tasks. We use a Bayesian point process model to estimate the system reliability. The prior distribution maps to a fault register and relates directly to a set of potential engineering modifications. The likely impact of each task can be assessed using the point process model. An integer programming approach is used to sequence and schedule tasks under the constraint that contractual reliability requirements must be met. An illustrative example is provided and an extension to system availability is proposed.