The optimization of crop seeds packaging production planning based on dynamic lot-sizing model

Crop seeds varieties and procurement constrain the seeds packaging planning.The automatic line packages faster but has higher setup cost than manual work.Setup, backlog and holding costs are considered in the objective function.Seeds packaging planning is optimized by a MILP model and a heuristic algorithm.The heuristic algorithm keeps beneficial under different parameters setting. With the competitive seeds market and development needs of seed companies, the production of crop seeds, including raw seeds procurement, processing, storage, packaging, and logistics, is complicated. Seeds packaging is one of the most important phases, including automatic and manual packaging. Automatic packaging is highly efficient with high setup costs, whereas manual packaging is the opposite. It is difficult for the managers to make the packaging planning, i.e., the number of automatic and manual packaging, based on the forecasted demand. This problem is considered to be a special dynamic lot-sizing problem but it is more complex compared to the general ones. To deal with this problem, this paper proposes a mathematical programming model with the objective of minimizing the total costs. Because the problem is Non-Deterministic Polynomial (NP) hard, the computational time for solving this model is very long. Therefore, this paper proposes a heuristic algorithm (HA) to solve the problem. Numerical results showed that the total costs calculated by the proposed HA are close enough (8.12%) to the optimal total costs of the proposed model and 22.6% lower than the traditional planning. At different scenarios, the HA can keep beneficial and reliable to a certain extent. The proposed model and HA provided detailed illustration for understanding the complexity of the seeds packaging planning and were able to deal with real situations in the seed company.