Optimization is the process of evaluating the trade-offs between two things that seem to be in conflict.
For example, as you increase inspection, you increase costs but you decrease the defects that get through. If you shorten your production runs, you can reduce your inventory but your production will decrease because change-over time required to change machines from producing A to producing B means more downtime.
With optimization, you try to find the exact point that minimizes the total cost.
But every optimization problem has some “givens.”
Taiichi Ohno, creator of the Toyota Production System, and his followers achieved breakthroughs by shifting their focus from finding the best trade-off to working on these “givens.”
When we talk about root cause analysis, we mean to focus on those “givens” or “underlying assumptions” that cause you to try to find the path of least waste.
Once you find and address the underlying cause, assumption, or given, you can find and move to an optimum that is at a totally
new level – often referenced as the “Imagineered level,” or the way things could or should be if everything was right!