Scheduling — critical path, Gantt, dependencies

How CPM works

Build the WBS. Estimate each leaf. Identify dependencies (this task needs that one finished first). Walk forward to compute earliest-start / earliest-finish dates. Walk backward to compute latest-start / latest-finish without delaying the project. Tasks where ES = LS have zero float — they're on the critical path.

Float — the buffer you didn't know you had

A non-critical task with 5 days of float can slip 5 days without delaying the project. Use float when you need to share a resource: free up the critical-path person by letting a float-rich task wait. But once float is consumed, the task becomes critical — track float as carefully as the critical path itself.

↳ schedule compression

Two ways to shorten a schedule on the critical path: fast-tracking (run sequential tasks in parallel — adds risk) and crashing (throw money / people at it — adds cost). Both are explicit trade-offs; they're tools the PM has when the date won't move.

The Gantt chart

Henry Gantt's 1910s contribution: tasks as horizontal bars on a time axis, with arrows for dependencies. The bolded path through the bars is the critical path. Useful as a communication artifact for sponsors and steering committees. Less useful for daily work — that's what your sprint board is for.

Scheduling — critical path, Gantt, dependencies.

How CPM works

Float — the buffer you didn't know you had

The Gantt chart

Sources cited

Further reading