Design optimization and redundant dependency study of series k - out - of - n : G repairable systems

This paper proposes a new optimization approach to find the best redundancy allocation of dependent repairable series k-out-of-n : G system using ant colony optimization. A model for the failure redundant dependency between the system components is formulated. It is considered in the system performance evaluation. An optimization model is then derived to be solved using the software LINGO and the proposed ACO algorithm. The objective consists of minimizing the system cost while satisfying a required level of system availability. The best system configuration in terms of number of components and number of repair teams in each subsystem is to be determined. The components are characterized by their failure rate, repair rate, unit acquisition cost and unit repair cost. In order to validate the proposed approach, an illustrative example is applied. A comparison between LINGO and ACO results is facilitated. The results show that the redundant dependency may positively affect the design configuration and the system cost. Furthermore, the proposed ACO outperforms LINGO for large scale systems in term of solution quality.