Six sigma quality process
If you want to improve somewhere quality, you can view sig sigma process as one of the possibilities. In six sigma you need to break whole process which one you plan to change, into each small individual pieces. That will be your steps, for improvement. Then in each step select what is wrong and what is correct, in order to reject something or stay as it is. After you need to measure number of rejects...or lets call it areas of improvements...steps for improvements. Each step for improvement has to have or try to identify, the root of the issue for the improvement. You need to see what cause the process to be the rejected and how it can be improved. After you need suggest what change for the each root can be implemented. Select the best ideas for each root and start implementing them into action. View constantly what outcome you are getting, remeasure and hold on the particular level if you satisfy with the outcome. Difficulties part here to hold the desired performance after the change at the defined level. Usually companies think that after few week or month the change no needed to be controlled and it already happens...but...it is wrong. The change usually the process which should be controlled between 6 month and 2 years. That gap usually enough for the change to be fixed. Nothing not change fast...if it change, then only for the short time. Bring the change, keep the change and never go back with performance level, otherwise you will loose time, money and resources.