Relocation problems of maximizing new capacities under a common due date

Abstract

Abstract Given a set of h buildings to be torn down and rebuilt, each building Bi , demands ni units of temporary vacancies for reconstruction (i.e. the reconstruction of Bi can be started only if there are at least ni temporary vacancies available) and returns ai units of vacancies when it is rebuilt. The reconstruction time of each building is assumed to be unitary. Under the initial provision of V o units of vacancies and a specified due date d, ΣBieSa i , where S is a feasible sequence such that |S| ≤ d, is the objective function to be maximized. We show that the problem is NP-complete. Based on a dominance heuristics, we further propose a branch-and-bound algorithm. Experimental results are included to elucidate the effectiveness of our algorithm. Two further restricted versions are also polynomially solvable.