Selective Regression Testing of a Host to DotNet Migration

This paper describes an industrial migration project in the years 2003/2004. At this time the Austrian Chamber of Commerce was moving its entire software portfolio from an IBM mainframe to a DotNet environment. The company of the author was contracted to test the redeveloped systems. The approach taken was selective regression testing, a method whereby selected, critical results are verified by comparing them against the same results of the old system. To achieve this, special tools based on an assertion language for defining post conditions of data files and databases were developed. This testing method turned out to be both effective and inexpensive