This thesis presents algorithms for the solution of the multi-period facility phase-out, phase-in problem in the uncapacitated case.
The problem can be stated that a number of sites are available at which facilities can be established to provide a set of services to given demand points over a planning horizon of T time periods. The demand in each time period must be satisfied and a fixed charge is associated with opening a facility at a site, and in phase-out(in) problem, a facility once closed(opened) is assumed to remain close (open) throughout the planning horizon T. The objective is to determine a set of facilities to open which minimizes the overall cost of opening, and transportation over the planning horizon.
The facility location problem as stated above has been solved by many other approaches. In this thesis, the dual ascent procedure which is based on the dual formulation of linear programming and the branch-and-bound procedure are used. For the dual ascent procedure, condensed constraints of the phase-out, phase-in problem are developed, and the dual descent procedure is developed to supplement the dual ascent procedure.
