Article ID: | iaor20071353 |
Country: | Netherlands |
Volume: | 3 |
Issue: | 4 |
Start Page Number: | 366 |
End Page Number: | 381 |
Publication Date: | Dec 2006 |
Journal: | Discrete Optimization |
Authors: | Lin B.M.T., Kononov A.V. |
Keywords: | location, construction & architecture, scheduling |
The relocation problem was formulated from a public housing project. In its basic form, a set of buildings needed to be torn down and erected by a single working crew. Given a fixed budget, the relocation problem seeks to determine a feasible reconstruction sequence of the old buildings. This problem has been shown to be mathematically equivalent to the classical two-machine flowshop of makespan minimization. In this paper, we consider a variant where multiple working crews are available for the redevelopment project. Most of our results center on the situations where all buildings require the same redevelopment time. We first present a strong NP-hardness proof for the case with two working crews. Then, we give a negative result about the approximability of the studied problem. Approximation algorithms and associated performance-ratio analysis are designed for the cases with unbounded as well as bounded numbers of machines.