Down-Menu*/ .nav li ul {position: absolute; padding: 20px 0; width: 300px;}

The amount of time a task can be extended or delayed before it impacts on the starting time of other tasks. Tasks A and B start at the same time. Task C is dependent on both tasks A and B. Task A takes 2 days and task B takes 5 days. Task A has 3 days’ slack. It can run 3 days overtime before it affects the planned starting time for task C.