What Is the Difference Between Free Slack and Total Slack?
Free slack is the amount of time in a schedule that can be taken before the next task is delayed. Total slack is the amount of time in a schedule that a task can be delayed before an entire project's completion date is delayed.
Slack is the amount of time that can be afforded to the delay or procrastination of a task before it adversely affects other tasks. Knowing the amount of slack in a schedule helps balance the schedule by relocating tasks that have too much slack between tasks or not enough slack to allow for unforeseen emergencies or other tasks that need to be addressed.