Sharif University of Technology Scientia Iranica 1026-3098 27 2 2020 04 01 Presenting a series-parallel redundancy allocation problem with multi-state components using recursive algorithm and meta-heuristic 970 982 21134 10.24200/sci.2018.51176.2040 EN M. Sharifi Faculty of Industrial & Mechanical Engineering, Qazvin Branch, Islamic Azad University, Qazvin, Iran 0000-0002-7682-7077 M. Saadvandi Faculty of Industrial & Mechanical Engineering, Qazvin Branch, Islamic Azad University, Qazvin, Iran. M. R. Shahriari Faculty of Management & Accounting, South Tehran Branch, Islamic Azad University, Tehran, Iran. Journal Article 2018 06 09 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. https://scientiairanica.sharif.edu/article_21134_520115043d9ba527a787577bd75930c8.pdf