Change Isn't Free: Impact Analysis

True Stories - The need for impact analysis is obvious for major enhancements. However, unexpected complications can lurk below the surface of even minor change requests. 

A company once had to change the text of one error message in its product. 

What could be simpler? 

The product was available in both English and German language versions. 

There were no problems in English, but in German the new message exceeded the maximum character length allocated for error message displays in both the message box and a database. 

Coping with this apparently simple change request turned out to be much more work than the developer had anticipated when he promised a quick turnaround.

Impact analysis is a key aspect of responsible requirements management (Arnold and Bohner 1996). 

It provides accurate understanding of the implications of a proposed change, which helps the team make informed business decisions about which proposals to approve. 

The analysis examines the proposed change to identify components that might have to be created, modified, or discarded and to estimate the effort associated with implementing the change. 

Before a developer says, "Sure, no problem" in response to a change request, he or she should spend a little time on impact analysis.

Trap - Because people don't like to say "no," it's easy to accumulate a huge backlog of approved change requests.
Before accepting a proposed change, make sure you understand the rationale behind it, its alignment with the product vision, and the business value that the change will provide.