http://www.usc.edu/dept/ise/caie/Checked%20Papers%20%5Bruhi%2012th%20sept%5D/word%20format%20papers/REGISTRATION%20PAID%20PAPERS%20FOR%20PROCEEDINGS/pdf/94%2012%20MILP%20MODEL%20FOR%20SOLVING%20THE%20SUPPLY%20CHAIN%20OPERATIONS%20SCHEDULING%20PROBLEM%20WITH%20ALTERNATIVE%20OPERATIONS%20CONSIDERING%20DEL.pdf
This paper addresses a mixed integer linear programming model for operations lot-sizing
and scheduling (assignment and sequencing) in the supply network of a European company which assembles customized machine tools through several geographically distributed factories and delivers them to the customers’ factory. The results from the model propose a schedule to purchase raw material from different suppliers to the various factories considered, lateral stock transshipments, shipments to customers and various operations required for product assembly. Different alternative operations (product substitution, alternative procurement and transport operations), considering lead times, are contemplated. Specific constraints, such as space availability in each plant and the two backlog types, are considered. A novel approach based on the stroke concept is applied to the MILP model to consider alternatives. Since the latest MILP optimizers are not always available, a specific procedure to solve the case study based on the graph theory is proposed. Moreover, thanks to this concept, the algorithm proposed determines all the feasible solution