What is critical path method?

Example: You are preparing a dinner for eight people. The recipe has twenty steps, and you treat them as a linear list: chop vegetables, then boil water, then marinate meat, then preheat the oven, then set the table. Dinner takes three hours because you never let two steps overlap. Your partner walks in and starts setting the table while you chop vegetables, boils water while the meat marinates, preheats the oven at the very beginning because it requires no prior output. The same twenty steps now finish in ninety minutes. Nothing about the tasks changed. What changed was the recognition that most of those steps had no dependency on each other — they only felt sequential because they were written in a list.

This concept is part of Workflow Design in the How to Think curriculum.