Abstract: The present invention relates to a repair program for multiple versions of computer programs that have a common error by using a pattern search and substitution technique. The invention includes identifying a common error in a main computer program, finding a common code section that contains the common error, and locating a segment of the common code section that is modifiable. The code section is then modified by optimizing the code to perform the same functionality and adding additional code to correct the error. A repair program is then written to search other versions of the main computer program and perform the modification step automatically without having to manipulate the source or machine code manually on the various versions of the software.