<Li> float or slack is a measure of the excess time and resources available to complete a task . It is the amount of time that a project task can be delayed without causing a delay in any subsequent tasks (free float) or the whole project (total float). Positive slack would indicate ahead of schedule; negative slack would indicate behind schedule; and zero slack would indicate on schedule . </Li> <Li> critical path: the longest possible continuous pathway taken from the initial event to the terminal event . It determines the total calendar time required for the project; and, therefore, any time delays along the critical path will delay the reaching of the terminal event by at least the same amount . </Li> <Li> critical activity: An activity that has total float equal to zero . An activity with zero float is not necessarily on the critical path since its path may not be the longest . </Li> <Li> Lead time: the time by which a predecessor event must be completed in order to allow sufficient time for the activities that must elapse before a specific PERT event reaches completion . </Li>

Pert provides the framework with which a project can be described scheduled and the controlled