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