ILOG CPLEX Extensions to MPS Format

Historically, MPS format (including ILOG CPLEX MPS format for ILOG CPLEX version 2.1 and earlier releases) included restrictions, such as requiring input fields to occupy fixed columnar positions and limiting all names to a length of 8 characters or fewer. In ILOG CPLEX Version 3.0 and subsequent releases, these restrictions have been relaxed. The current ILOG CPLEX MPS format is actually an extended version of the historical MPS format. To allow for these extensions, certain practices which were accepted in MPS files for older ILOG CPLEX releases and other systems are no longer permitted. For example, since ILOG CPLEX no longer requires fixed columnar positions, blank spaces are interpreted as delimiters. Older MPS files containing names with embedded spaces would therefore become unreadable. To maintain compatibility with earlier ILOG CPLEX versions as well as MPS files from other systems, ILOG CPLEX provides an MPS file conversion utility which translates older files into the new ILOG CPLEX MPS format. The CPLEX User's Manual explains how to use the file conversion utility.