Pocket PMOPut a statistical number on the change request, while you are still in the room.
Put a statistical number on a change request while you are still in the room. PERT and Monte Carlo give independent consultants the defensible range a promise never has.
Three conversations consultants have every month
A client adds scope mid-delivery. Instead of “that will affect the timeline”, you show the new probability for the committed date and the delta it costs. The argument about whether the change is small ends before it starts. You need to name a buffer without inventing one. PERT converts your best/likely/worst ranges into a defensible range, and the P80 becomes the number you quote with a reason attached. Proposals that carry “delivery probability 80% by [date]” read differently from proposals that carry a promise. Buyers of professional services notice the difference.
The spreadsheet route was built for someone with more patience than you
No install, no training week, no modelling team. Client-visible output in seconds, a multi-project view for client accounts, and forecasts you can send as a link.
Prove it on the project that is worrying you right now
Take the engagement with the date you are least sure about. Run its tasks through the sizer. If the P80 number is not more useful than the hedge you were going to write, close the tab; it cost you nothing.
Run the example on your own schedule
Run its tasks through the sizer in Pocket PMO: if the P80 number is not more useful than the hedge you were going to write, close the tab; it cost you nothing.