Panel on: "How much has software maintenance changed since 1983?"

What are the important developments in software maintenance since 1983?. Is there quantitative proof or even qualitative evidence that these developments have made maintenance less expensive or easier to perform? How have developments and practices in managing software maintenance, reengineering, reverse engineering, program comprehension, impact analysis, maintenance tools, maintenance process, maintenance models, maintenance standards, and measurement of maintenance changed the quality and cost of maintenance since 1983?. These issues are addressed.