Home → Techniques and Tips → @RISK 6.x/7.x with Projects → Critical Index of Summary Tasks
Applies to: @RISK 6.x/7.x, Professional and Industrial Editions
In the Probabilistic Gantt chart, I see critical indices for summary tasks. How are they computed?
When using the Standard Engine, @RISK relies on Microsoft Project to determine critical paths. The critical path found by Project may include regular tasks and summary tasks. @RISK counts the number of iterations where a given task of either type is on the critical path, divides by the total number of iterations, and reports the resulting percentage as the critical index for that task.
When using the Accelerated Engine, @RISK determines the critical path based on individual tasks. Summary tasks are never considered part of the critical path, and therefore @RISK reports "n/a" (not applicable) as the critical index for summary tasks.
You can select an engine in the Project Settings dialog in @RISK. Use Check Engine in that dialog to determine whether your project can use the Accelerated Engine, or what issues require it to use the Standard Engine.
Last edited: 2015-09-01