Hi Steve -
We began using Allocate from Estimates on a very large program about six months ago to help manage resource utilization across multiple project schedules. Our schedulers use MSP 2010 and all team members are required to report time weekly using the CA PPM Timesheet. We use custom fields on the Team to track Approved Start, Approved Finish and Approved % to counter-act the business rules associated with Avail Start, Avail Finish, and Default % in CA PPM.
I have observed the following when using Allocate from Estimates:
1. Leave Allocation Start/Finish blank and enter Default % only. Avail Start and Avail Finish are blank by default when a new team member is allocated to the project. When these fields remain in this state and you Allocate from Estimates, the team member's Avail Start and Avail Finish will continue to match the Project Start/Finish dates, and the Default % retains it's original value, even after time sheets post and the schedule is "round-tripped" between CA PPM and MSP.
2. Enter dates in the Avail Start and Avail Finish fields in addition to the Default %, post time sheets, round-trip the schedule to/from MSP, then Allocate from Estimates, I observed the following:
--- Avail Start becomes the date the first actual hour is posted. (This change occurs only once as Allocate from Estimates updates segments after the Actuals Thru date.)
--- Avail Finish becomes the latest assignment finish
--- Default % changes to a strange percentage (ex. from 25% to 87.3%).
The changes to Avail Start and Avail Finish make sense. However, I spent months researching the changes to the Default % as it changed every week and I was not able to track the value to anything in the current timeframe (ex., Total Assignment Allocation for the current day in MSP). To get around this issue during my research, I created custom Approved Start, Approved Finish and Approved % fields for the Resource Managers to track the data the need as they were frustrated by the weekly, unexplained changes.
In December, I finally stumbled on a KB article related the business rules associated with the OTB fields (Avail Start, Avail Finish and Default %) when using Allocate from Estimates, and Avail Finish seems to be the key player. When When the Avail Finish is left blank, the Avail Start and Default % retain their entered values. When you enter data in Avail Finish, the dates will change as in scenario 2, and the Default % changes to the % of the latest Allocation Segment for that team member. So, if their assignment load on the last day of their commitment to the project is 5%, then the Default % will change from the entered value (ex. 25%) to 5%.
It sounds like you want the Start/Finish dates to update based on assignments, so you would want to enter data in the Avail Start and Avail Finish fields. However, you should be aware of the impact to the Default % field if that is important to your organization.
I hope this information is helpful.
Katie