“A Project is complete when it starts working for you than you working for it” – Scott Allen If one is looking for a tool to analyze and represent tasks regarding a project , the best statistical tool in project management would be PERT.Now, PERT has an interesting fact that it can schedule a project without knowing the details and durations of all the activities. Talking in terms of its application , it can be applied to complex ,one-time Research and Development Projects. It was developed for the US Navy Special Projects Office in 1957 to support the U.S.
Navy’s Polaris nuclear submarine project.So quickly lets talk about the PERT terminology PERT event: a point marking the start or completion of one or more activities. It consumes no time and uses no resourcespredecessor event: an event that immediately precedes some other event without any other events intervening. successor event: an event that immediately follows some other event without any other intervening events.Besides events, PERT also knows activities and sub-activities:PERT activity: the actual performance of a task which consumes time and requires resources A PERT activity cannot be performed until the predecessor event has occurred.PERT sub-activity: a PERT activity can be further decomposed into a set of sub-activities. For example, activity C1 can be decomposed into C1.
1, C1.2 and C1.3.. A sub-activity can be decomposed again into finer-grained sub-activity.
As we have discussed about event and activity, PERT also defines four type of time Optimistic Time-The minimal time required to complete a task or activityPessimistic Time- The maximum time required to complete a task or activityMost Likely Time- The optimum approx time required to complete the task or activity,considering there are no problemsExpected Time-The optimum approx time required to complete the task or activity. Now lets see how to create a PERT chart,So there are specific terms related to pert chart lets discuss that first.Slack- Its the delay that can be provided to a task without affecting the project overall.Critical Path- The longest possible path from beginning to the end of a task or activityCritical Path Activity- Basically it infers zero slackLead time-Time consumed by a particular task without affecting the task following it.Lag time-The untimely time one task can follow another.Fast tracking- Working more than one task in parallel.Crashing critical path- Lessening the time of a task.