Standards families
PERT / CPM network
Activities as a dependency network with durations — the critical path read off the longest chain.
pert.cpm@1New DDN source
Why use it?
Schedule risk lives on the critical path; the network makes "what slips the date" a computable question.
When it helps
Project planning where dependencies, not calendars, drive the end date.
How to read it
- Nodes/boxes are activities with durations; arrows are finish-to-start dependencies.
- The longest path is the critical one — any delay on it moves the end date one-for-one.
What you need
- The activities with durations
- The dependencies between them
Things to check
- Do not add a dependency to force a resource fit — that is a resource problem wearing a logic costume.
- A cycle in the network is a planning error, not a paradox.
Scope of this diagram
Declared network; path arithmetic follows the declared durations, estimation method is yours to document.
Work with the converted example
- Open the viewer and select
plan. Inspect the rendered view and its source. - Open the designer. Keep the selected profile and inspect its legal palette and property controls.
- Change one displayed title or an appropriate data value. Apply the edit and check the resulting diagram.
- Run the verifier and review its diagnostics before moving complete content into review.
- Download your edited DDN source to retain the change.
The example uses the indentation-based ddn-next-1 dialect. The language guide explains reusable definitions, dotted data rows and explicit property blocks.