Integration of order scheduling with delivery vehicles routing for two-echelon supply chain system

This study considers together machine scheduling and finished product delivery. A single machine scheduling model is developed that incorporated delivery vehicle routing decisions which serves one customer location with multiple vehicles. The objective is to minimize makespan. The problem is NP-hard in the strong sense in general. A mixed binary integer programming model is developed to optimally solve this problem. Also, an illustrated example is proposed to find the optimal schedule using the proposed model.