Multi-level supply chain network Design based on the multiple objectives of reliability, cost and delivery time using a meta-heuristic solution method

Reliability is an important indicator that should be taken into account when making strategic decisions in the design of the supply chain so that the system continues to function with the least loss when a member malfunctions or fails. In this article, an attempt is made to reduce the long-term costs of the chain and increase the service level by increasing the reliability. One of the innovations of this article is to present a new method for calculating the supply chain reliability index according to the definition and nature of reliability. Calculating the reliability of each of the levels with the calculation method of parallel systems is not correct, according to the proof in the text of the article, and the reliability of each member should be based on the amount of product or raw materials that each member supplies from that level. Produce or maintain, be different that these cases were not considered in the previous research. Value is the final indicator of the success of a system. In this article, the value of the supply chain is defined using three indicators of the SCOR model, including cost, responsiveness (delivery time) and reliability. The proposed model belongs to the category of non-linear integer programming problems (MINLP), which is designed with the aim of maximizing the value of the supply chain. Due to the complexity of the problem in large dimensions and proving that it is NP-hard, the meta-heuristic algorithm developed by genetics has been used to solve it.