presenting a series-parallel redundancy allocation problem with multi-state components using recursive algorithm and meta-heuristic

Redundancy allocation problem (rap) is one of the most important problems in the field of reliability. this problem aims to increase system reliability, under constraints such as cost, weight, etc. in this paper, we work on a system with series-parallel configuration and multi-state components. to draw the problem nearer to real condition, we merge this problem with discount levels in purchasing components. for calculating sub-systems reliability, we used recursive algorithm. because rap belongs to np. hard problems, for optimizing the presented model a new genetic algorithm (ga) was used. the algorithm parameters tuned using response surface methodology (rsm) and for validation of ga an enumeration method was used.