What is a CPM schedule?

A critical path method (CPM) schedule is a project timeline that maps task dependencies to compute the longest chain of work — the 'critical path' that drives the finish date.

CPM calculates each task's earliest and latest start and finish and its float (slack). Tasks with zero float are on the critical path: delay one and you delay the whole project.

It turns a list of activities into a defensible, recomputable schedule rather than a static bar chart.