You optimise a system by looking at the whole flow, not by making the fastest part faster

A process is a chain of steps, and it is tempting to improve the step that is easiest to see, or the one that seems most obvious. But making a step faster only helps if that step is the bottleneck. If it is not, the work piles up in front of the next step, which is still the real constraint. The question that matters is not how to make one part faster, but what a change does to the whole flow. Skip that question and you optimise inside an illusion of progress: a fine result at one station, while the total lead time stays the same or gets worse. This holds for personal effectiveness as much as for a production line. Finishing a task faster only helps if that task is where the work gets stuck. Otherwise you are just moving the queue. Related Start with as little as possible and add complexity as you go