Data Type Duration
Entry Type Calculated
Description The Finish Slack field contains the duration between the Early Finish and Late Finish dates. The smaller of the finish slack and start slack amounts determines the amount of free slack available, that is, the amount of time a task can be delayed without affecting the start date of a successor task or the project finish date.
How Calculated Finish slack is the duration that represents the difference between the late finish and early finish dates. The early finish is the earliest date that a task could possibly finish. Likewise, the late finish field contains the latest date that a task can finish without delaying the finish of the project. Project calculates the finish slack as follows:
Finish Slack = Late Finish - Early Finish
Best Uses Add the Start Slack and Finish Slack fields to any task view when you want to review how free slack was calculated.
Example You are reviewing free slack in your schedule and want to see more details about how it was calculated. You add the Start Slack and Finish Slack fields to the task sheet and analyze the durations.
Remarks If a task has an actual start date and also a deadline set, the start slack will be 0 and the finish slack will be the difference between the task's finish date and deadline date.