A support environment to facilitate software transportation
Stephen M. Jodis · 1994
The need for a method to reduce software maintenance costs incurred in performing adaptive maintenance on software systems led to the definition of the Transportable Programming Language (TPL) System in 1976 by P.A.D. de Maine, et.al. Adaptive maintenance costs occur when an existing software system is moved from one environment (language, dialect, or hardware system) to another. The instrument for achieving this objective was defined in 1986 by Soklei Leong, and is known as the Conversion Rule Description Language (CRDL). A methodology for using the CRDL to write conversion descriptions between various environments was described by Stephen Jodis in 1987. A primary objective of the TPL/CRDL system was to provide an environment in which computer professionals would develop CRDL conversion descriptions between different environments and make them available, via a public library, to other computing professionals. This objective required the TPL/CRDL environment to be more user friendly. This dissertation presents tools which attempt to provide this user friendliness to computer users who must convert code from one software environment to another. An overview of software maintenance, its costs, and an examination of current research trends for reducing this cost is presented. This thesis also includes a brief description of how these other software maintenance research areas differ from the TPL system, and a detailed description of the TPL/CRDL tools which attempt to reduce software maintenance cost in the area of adaptive software maintenance. Finally, the dissertation includes a conversion report which describes the movement of the TPL/CRDL Compiler and Assembler from the VAX FORTRAN 77 environment to the Sun f77 environment.