For the last seven weeks we have been working on some significant upgrades to our architecture and packaging.    During this time, we have also been tracking work to fix bugs and irritating behavior in the existing features.  I wondered why we couldn't close this list and move on, and I discovered, under the seven open issues, that we had more than 200 closed tickets.

It reminds me of the circus act where a small car drives into the ring, and 18 clowns get out.  They just keep coming out.  In this case, 200 clowns came out. 

This is a typical dynamic as systems get larger and have more function points.  Fortunately, we don't specify a fixed set of tasks when we begin our iterations.  We keep adding items and fixing them until it is time to stabilize for a release.  I know that many of our customers do like to have a fixed plan for their iteration, and I wonder how they handle the need for taking care of these clowns, every week.