This paper studies location routing and scheduling problems, a class of problems in which the decisions of facility location, vehicle routing, and route assignment are optimized simultaneously. For a version with capacity and time restrictions, two formulations are presented, one graph-based and one set-partitioning-based. For the set-partitioning-based formulation, valid inequalities are identified and their effectiveness is demonstrated empirically. Two versions of a branch-and-price algorithm are described and the results of computational experiments for instances with 25 and 40 customers are discussed.
Technical Report, COR@L Laboratory, Department of Industrial and Systems Engineering, Lehigh University.