Solving the Traveling Repairman problem with differentiated waiting times through Lagrangian relaxation

In this paper we present a formulation of the traveling repairman problem with differentiated waiting times that is derived from the extended disaggregated flow formulation for the asymmetric traveling salesman problem. We focus on the usage of the Lagrangian approach as a mechanism of speeding up the solution of the linear relaxation by a simplex method. We show some computational results.