An Optimal Policy for Solving a Generalized Problem of Constrained Redundancy Allocation in Coherent Systems

SYNOPTIC ABSTRACT

Redundancy is an important aspect of system design. The use of redundancy improves system reliability. In the case of systems whose cost of failure is very high, redundancy may be used to make the system fail-safe, and thus, in any safety-critical systems, a proper use of redundancy is essential. Because adding redundancy increases the total cost and complexity of a system design, it should be used wisely, taking the cost and other constraints into account. The question arises with regard to how many redundant components should be added to different components or subsystems of a coherent system in order to maximize the system reliability. The problem becomes more difficult when the maximization is to be done under various constraints. The present study solves a redundancy allocation problem (RAP) in a complex system in an optimal way under various constraints involving cost, weight, volume, and so forth. The rule developed here can be used to maximize the reliability of any simple or complex coherent systems under any number of constraints. A numerical example has been included to illustrate the method.

Key Words and Phrases:

• coherent system
• redundancy allocation
• reliability optimization
• structure function
• system reliability