Starting Quality Assurance – Part 6
Have we been successful?
Last time we gathered some statistics based on the new process once it had settled down. Now we need to compare the new results with the baseline from before the changes were made. If the results have improved, then we keep the change we made. If things have not improved then we need to back out the change and measure again.
Once we have everything either at the same level as the baseline or improved, then we can embark on the next round of improvements using the same process.
Two things that can cause problems:
1. Sometimes the changes are interrelated. This will require research and a method of disentangling the impacts of the changes. Otherwise we may end up undoing the wrong change and find ourselves bouncing back and forth with no long term improvement.
2. We have to watch for noise in the system or special items that cause the measurements to be inconsistent. No two measurements will be identical and there will be some variation at some level. This has to be ignored or the measurements taken over a long enough time period to even out any variations due to noise in the system. The other item that has to be watched is some special item like a large project or a freeze on development that will cause either the baseline or the new measurements to be inaccurate. Either an adjustment will have to be made or the measurements excluded from the calculation.