A Simulated Annealing Algorithm for Fuzzy Reliability Optimization Model in Series-Parallel and Standby Systems

In recent years, reliability as a design characteristic of products has widespread applications in many industries including defense and aerospace industries and became attractive issue. The main aim of reliability engineering is to improve system performance. Use of redundancy components is one of the ways for reliability improvement, although usually it is not possible to gain exact data in this type of systems to determine optimum number of redundancy components. Therefore, fuzzy logic has been introduced for assessing and analyzing the systems. This study presents a mathematical model for optimal allocation of the number of redundant components at each stage of multi-stage systems with structures such as parallel-series and standby to maximize system reliability subjecting to cost and weight constraints; which in this model reliability and cost and weight of each components and cost and weight of system are considered as fuzzy parameters. At last a numerical example regarding to triangular and trapezoidal fuzzy numbers and using different methods for defuzzification is surveyed and value of variables is computed with a simulated annealing meta-heuristic approach and the results are presented.