Back to basics.

3 variables in delivering a product: Function/Quality; Time; Dollars. Lay out the plan and get commitment from Development to all 3. When (not if...) things start slipping, alter the plan - add more time, drop function, or (last priority) throw more people at it. The magic "sauce" is in your Business Case - you have got to have a Business Case for the project - update the BC with the new figures and report back to management the revised expectations. This is not a personal attack against Development, but takes a critical view of project(s) as a BUSINESS decision - if we can't deliver in the time expected, then the ROI, revenue, competitive positioning, etc. will be impacted. "Aw Shucks" just isn't an acceptable answer anymore. Take personalities and blame out of it, and just show the facts.

"To meet our shipment goal, we will need to pull European support from this release. This will reduce our revenue expectation from $XM to $YM and delay profitability from 6 months to 2 years." Or, "we must move the deliver date X months due to Dev's inability to meet the original plan. Based on this, we suggest stopping the project altogether, since we will miss our market window of opportunity."

Agile development techniques increase Product Management's role in the planning process and should make you aware of slips earlier in the process to alter the plan. It requires increased time and dialog with the development team, but this may be necessary for you to get more on top of schedule slips.

Answered by John Milburn