Do you have any kind of update process?
Let's assume you are an "in-house" development shop for php inside your company. You are creating an bunch of applications for other units.
Do you have something like "Support ends in 2 years" ? What happens if you develop an app for php 5.3, and this app can't run with php "6", or another framework you use will no longer be maintained?
Would love to hear some ideas :-)