ILOG CPLEX 11.0 File Formats > > ILOG CPLEX File Formats > MPS File Format: Industry Standard > ILOG CPLEX Extensions to MPS Format

Historically, MPS format (including CPLEX MPS format for 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 CPLEX version 3.0 and subsequent releases, these restrictions were 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 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 therefore become unreadable. To maintain compatibility with earlier versions as well as MPS files from other systems, ILOG CPLEX provides an MPS file conversion utility which translates older files into the newer ILOG CPLEX MPS format. The section Converting File Formats in the ILOG CPLEX User's Manual explains how to use the file conversion utility.