2004/01/01 by Vijay Arya, Naveen Garg, Rohit Khandekar +3 · 547 citations
Business, Management and Accounting · Computer Science · Engineering · Mathematics · #1-center problem #Bounded function #Computer science #Facility Location and Emergency Management #Facility location problem #Heuristic #Heuristics #Local search (optimization) #Locality #Mathematical optimization #Mathematics #Metric (unit) #Minification #Optimization and Search Problems #Vehicle Routing Optimization Methods
paper · doi:10.1137/s0097539702416402
published in SIAM Journal on Computing 33(3), 544-562 (Society for Industrial and Applied Mathematics)
openalex publication_date 2004/01/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/26
We analyze local search heuristics for the metric k-median and facility location problems. We define the locality gap of a local search procedure for a minimization problem as the maximum ratio of a locally optimum solution (obtained using this procedure) to the global optimum. For k-median, we show that local search with swaps has a locality gap of 5. Furthermore, if we permit up to p facilities to be swapped simultaneously, then the locality gap is 3+2/p. This is the first analysis of a local search for k-median that provides a bounded performance guarantee with only k medians. This also improves the previous known 4 approximation for this problem. For uncapacitated facility location, we show that local search, which permits adding, dropping, and swapping a facility, has a locality gap of 3. This improves the bound of 5 given by M. Korupolu, C. Plaxton, and R. Rajaraman [Analysis of a Local Search Heuristic for Facility Location Problems, Technical Report 98-30, DIMACS, 1998]. We also consider a capacitated facility location problem where each facility has a capacity and we are allowed to open multiple copies of a facility. For this problem we introduce a new local search operation which opens one or more copies of a facility and drops zero or more facilities. We prove that this local search has a locality gap between 3 and 4.