Integrated Production Scheduling in Dairy Products with Improved Particle Swarm Optimization

This study is concerned about how the quality of perishable products can be improved by shortening the time interval between production and distribution. Since special types of food, such as dairy products decay fast, the integration of production and distribution scheduling (IPDS) is investigated. This article deals with a variation of IPDS that contains a short shelf life product; hence, there is no inventory of the product in the process. Once a specific amount of products are produced, they must be transported with the least transportation time directly to various customer positions within its limited lifespan to minimize delivery and tardy costs required to complete producing and distributing the product to satisfy the demand of customers to the limited deadline.
After developing a mixed-integer nonlinear programming model of the problem, because it is NP-hard, an Improved Particle Swarm Optimization (IPSO) is proposed. IPSO performance is compared with a commercial optimization software for small-sized and large-sized problems. The model has developed as an Integer- nonlinear model and it solved by using an improved particle swarm optimization which is improved by 1-opt and 2-opt operator and is coded in Matlab program. The model has been investigated through the real data gathered from Pegah company and the outcomes has been compared to the previous order system.Computational experiments show the efficiency and effectiveness of the proposed IPSO in terms of both the quality of the solution and the time of achieving the best solution.