When you create an assignment, application automatically estimates time slots needed for a selected vendor to process an assignment (only if Enable workload planner for assignments setting is enabled in the application settings, under the Workload planner tab). This estimation is based on productivity settings specified in a vendor's profile and data specified in an assignment itself. Starting from assignment deadline, application searches for vendor free slots, and allocates volumes to the most possibly latest time slots. In the result you get Time tracking table filled with estimated data. This method is used to keep earlier time slots free, so if any more urgent assignment comes, you will have better understanding of vendor availability.

However, if default allocation does not work for you, you can edit estimated data manually, by removing or editing automatically-created rows in the Time tracking table. Upon any edit, Manual allocation checkbox will be selected, and starting from this moment application won't fill Time tracking table automatically, even if you make any changes to the tasks table, or any other fields. If you wish application to re-create time tracking rows automatically, uncheck this box and re-save an assignment.

Take a note: if total volume of the Time slots table exceeds average volume of an assignment, application will show an error and won't allow to save an assignment.