In Six Sigma, from what little I know about Six Sigma, you identify the outputs of your process that are ‘critical to quality.’ You then look to see if you can find the measures that can move those outputs. You work to drive these measures in a positive direction, quality goes up, and the requisite business benefits occur. Cool.
All this leads to process improvement.
Problem is: which process?
Lean manufacturing and the Theory of Constraints tells us that the process you pick to improve matters… a lot. If I improve a process that makes a non-key individual more efficient, there may be no effect whatsoever on the overall ability of the company to deliver value, make money, or even reduce cost. In addition, any time and effort I’ve invested in improving a process can, in some cases, make a person unwilling to change the process later, even if marketplace changes demand it, because “we spent all that time!”
So when you are trying to create a business case for an application, don’t just say “we will make Mary more efficient.” Tell the story of what Mary does, in relationship to the overall process of providing value to the company. Then it makes sense to invest in Mary. Then Mary is critical to quality. Then, any delay in Mary’s job means money is spent or revenue lost. Tie it back.
Otherwise, you may spend money making Mary more efficient when a smart move would have been to give Mary a more interesting job.