Data Type Date (date field: A type of field whose content is a date. Examples include the Baseline Start and Early Finish fields.)
Entry Type Calculated or entered (calculated or entered field: A field in which the value is determined by Project based on information in other fields. Information that you enter in the field yourself overrides calculated values.)
Description The Optimistic Start field contains the date that represents the best-case possibility for when a task could start. You can enter this date as part of a PERT analysis calculation, which takes a weighted average of expected, pessimistic, and optimistic dates and durations. This field is available only in the PA_Optimistic Case table or the PA_Optimistic Gantt view.
How Calculated When you first create a task, the Optimistic Start date field contains "NA." When you enter an optimistic duration and optimistic finish date, and then click Calculate PERT on the PERT Analysis toolbar, an optimistic start date for the selected task is calculated and placed in the Optimistic Start field.
Best Uses Use the Optimistic Start field in the PA_Optimistic Case table or the PA_Optimistic Gantt view to estimate the probabilities of task dates. By default, the PERT analysis calculation gives heaviest weight (4) to the expected information, and the lightest weight (1 each) to the pessimistic and optimistic information.
Example You have several critical tasks for which you want to see the best-case, worst-case, and expected start dates. You enter the expected finish dates and durations for these tasks, as well as their optimistic and pessimistic finish dates and durations, and then run the PERT analysis calculation.
Remarks By changing the weight that Microsoft Office Project attributes to each of the three estimated durations, you can tailor the probable estimate to be more accurate. To change the weight, click PERT Weights on the PERT Analysis toolbar, and then alter the default settings.
The Optimistic Start field uses the Start1 custom start date field.