One of the drawbacks of process improvement is looking at why things don't work (or are sub-optimal). It can be negative and for some people this can wear them down over time.
The successes we achieve as part of our process improvement work needs to be celebrated. I'm sure that your projects have yielded positive results and occasionally it is useful to stop and remember.
Not only does remembering the victories help inspire the next round of improvement, but it is good just to recall that fact that you have done good work up to this point.
The journey you have traveled already should be celebrated anyway. If you have left something in a better state than before you made your changes then you deserve a pat on the back.
Don't make process improvement just about picking on the things that are going wrong. Use your past successes as a spring board to reach new heights. The style of approach can make a big difference to the results you achieve in the long term.
Author of 'Business Process Re-Engineering', a practical plan to improve business performance.