Program evaluation and review technique
Program evaluation and review technique ppt
Navy and some of its contractors working on the Polaris missile project. Get free online marketing tips and resources delivered directly to your inbox. Laxmi Publications, Published on: Invalid date. When time estimates can be made with a high degree of certainty, they are called deterministic estimates. Since then, all government contractors have been required to use PERT or a similar project analysis technique for all major government contracts. Whichever path has the longest duration is the critical path, since shrinking this path will compress the duration of the entire project. If a manager hopes to shorten the time required to complete the project, he or she must focus on finding ways to reduce the time involved in activities along the critical path. Tasks that must be completed in sequence but that don't require resources or completion time are considered to have event dependency. The critical path must be closely monitored to ensure that a project is completed in a timely manner.
For example, it forces them to organize and quantify project information and provides them with a graphic display of the project. The critical path must be closely monitored to ensure that a project is completed in a timely manner.
PERT charts are often constructed from back to front because, for many projects, the end date is fixed and the contractor has front-end flexibility.
Each of these can be used for scheduling, but because Gantt charts don't illustrate task dependencies and PERT charts can be confusing, PMs often use both. The arrows represent activities in the activity-on-arrow convention, while the nodes represent activities in the activity-on-node convention.
Published on: Invalid date. The difference between the length of a given path and the length of the critical path is known as slack.
Program evaluation and review technique pdf
The tasks between nodes 1 and 2, and nodes 1 and 3 are not dependent on the completion of one to start the other and can be undertaken simultaneously. The network diagram consists of arrows and nodes and can be organized using one of two different conventions. The only real weakness of the PERT process is that the time required for completion of each task is very subjective and sometimes no better than a wild guess. The amount of time required to complete the work involved in any path can be figured by adding up the estimated times of all activities along that path. The direction of the arrows, and the numbers, indicate the required sequence. Project management charts: Beyond Gantt : Gantt charts are good for certain purposes, explains project management expert David Christiansen, but there are other charts PMs have at their disposal. The sequence of activities leading from the starting point of the diagram to the finishing point of the diagram is called a path. For complex problems involving hundreds of activities, computers are used to create and analyze the project networks. The chief disadvantages of PERT lie in the nature of reality. A PERT chart presents a graphic illustration of a project as a network diagram consisting of numbered nodes either circles or rectangles representing events, or milestones in the project linked by labelled vectors directional lines representing tasks in the project. PERT allows for the inclusion of variable amounts of time for each task. The critical path is that sequence of tasks that requires the longest total time period to complete.
Knowing where slack is located helps managers to allocate scarce resources and direct their efforts to control activities. These three estimates are then combined to arrive at a single estimated duration for each task.
Since these paths require less time to complete, they can often accommodate slippage without affecting the project completion time.
Whichever path has the longest duration is the critical path, since shrinking this path will compress the duration of the entire project. There may be several paths within a PERT chart, each comprised of a different set of interrelated tasks that must be completed.
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