Small in size. No external software interfaces. No additional functionality required. May include assembly or proprietary languages. Interfaces with external software.
Additional functionality is needed.
Calls to operating system routines. Not well defined. Minimal support for large-scale conversion. Project data from reengineering efforts should help define selection criteria for identifying information systems that benefit from reengineering. Currently, there is not enough data to support formal selection criteria for selecting information systems for software reengineering.