Critical Path Pro And Cons
The critical path is the path with activities that cannot be delayed under any circumstances. A proper knowledge about the stack values with limited conditions of dependencies will help the project manager to bring fast and quality decisions that will favor the project performance. Pros and Cons. The critical path method has stood the test of time since its creation in the 1950s at Du Pont. The benefit of the critical path method is that it lays out a sequence for the steps.
The program evaluation and review technique, or PERT, lets you schedule project tasks, assign resources and determine the critical path for a project. It is a powerful analytic tool that lets you manage tasks by applying a systematic approach to complicated projects. Although widely used, PERT is most effective when you are aware of its disadvantages and make allowances for its inaccuracies.
Changing Task Definitions
The PERT system forces you to define activities as independent tasks. They must be self-contained, with a start date, a duration, a defined cost and requiring defined resources. In the real world, situations may change as a project progresses. While you can revise PERT to take such changes into account, preparing the initial PERT chart for a project is time-consuming and labor-intensive. Making major modifications in the chart in mid-project is often difficult. As a result, you are working with a PERT chart that no longer accurately portrays the project.
Subjective Time Estimates
The PERT chart accepts subjective project manager estimates for the duration of activities. Its accuracy is limited by the reliability of each of the estimates of task duration. The chart remains reasonably accurate if some tasks take longer and some less time, according to a probability distribution . In real projects such a distribution may not apply, if a particular part of the work faces problems and all tasks in that area of activity are late. When the duration of these tasks increases, the tasks for which they are prerequisites are delayed, and you may have to make major revisions to the PERT chart to make it relevant again.
Near-Critical Paths
One of the key features of the PERT charts is the ability to display a critical path. The critical path is the sequence of project tasks that has the longest duration, and the total duration determines the completion date of the project. The PERT system tells you to focus on these critical tasks to ensure the project completion date remains unchanged. The chart may contain similar task sequences whose total duration is slightly less, and the tasks are therefore not critical. If one of these tasks takes longer than estimated, the critical path may shift as the new sequence becomes the one with the longest duration. In this case you have been focusing on the wrong tasks.
Changing Task Relationships
The PERT charts and the critical path calculations rest on tasks that have prerequisites and dependencies. In real projects, when you find that you can't meet the required prerequisites for a task, you make alternative arrangements. For example, if your power supply is going to be six months late, you might rent a generator. PERT charts are not flexible in this respect and you would have to prepare a completely revised chart. PERT charts are most effective on projects dealing with well-known processes and for which experienced personnel can accurately determine the required activities and their duration.
References
About the Author
Bert Markgraf is a freelance writer with a strong science and engineering background. He started writing technical papers while working as an engineer in the 1980s. More recently, after starting his own business in IT, he helped organize an online community for which he wrote and edited articles as managing editor, business and economics. He holds a Bachelor of Science degree from McGill University.
Photo Credits
- Polka Dot Images/Polka Dot/Getty Images
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Critical Path Pro And Cons Free
The program evaluation and review technique, or PERT, lets you schedule project tasks, assign resources and determine the critical path for a project. It is a powerful analytic tool that lets you manage tasks by applying a systematic approach to complicated projects. Although widely used, PERT is most effective when you are aware of its disadvantages and make allowances for its inaccuracies.
Changing Task Definitions
The PERT system forces you to define activities as independent tasks. They must be self-contained, with a start date, a duration, a defined cost and requiring defined resources. In the real world, situations may change as a project progresses. While you can revise PERT to take such changes into account, preparing the initial PERT chart for a project is time-consuming and labor-intensive. Making major modifications in the chart in mid-project is often difficult. As a result, you are working with a PERT chart that no longer accurately portrays the project.
Subjective Time Estimates
The PERT chart accepts subjective project manager estimates for the duration of activities. Its accuracy is limited by the reliability of each of the estimates of task duration. The chart remains reasonably accurate if some tasks take longer and some less time, according to a probability distribution . In real projects such a distribution may not apply, if a particular part of the work faces problems and all tasks in that area of activity are late. When the duration of these tasks increases, the tasks for which they are prerequisites are delayed, and you may have to make major revisions to the PERT chart to make it relevant again.
Near-Critical Paths
One of the key features of the PERT charts is the ability to display a critical path. The critical path is the sequence of project tasks that has the longest duration, and the total duration determines the completion date of the project. The PERT system tells you to focus on these critical tasks to ensure the project completion date remains unchanged. The chart may contain similar task sequences whose total duration is slightly less, and the tasks are therefore not critical. If one of these tasks takes longer than estimated, the critical path may shift as the new sequence becomes the one with the longest duration. In this case you have been focusing on the wrong tasks.
Changing Task Relationships
The PERT charts and the critical path calculations rest on tasks that have prerequisites and dependencies. In real projects, when you find that you can't meet the required prerequisites for a task, you make alternative arrangements. For example, if your power supply is going to be six months late, you might rent a generator. PERT charts are not flexible in this respect and you would have to prepare a completely revised chart. PERT charts are most effective on projects dealing with well-known processes and for which experienced personnel can accurately determine the required activities and their duration.
References
About the Author
Critical Path Software
Bert Markgraf is a freelance writer with a strong science and engineering background. He started writing technical papers while working as an engineer in the 1980s. More recently, after starting his own business in IT, he helped organize an online community for which he wrote and edited articles as managing editor, business and economics. He holds a Bachelor of Science degree from McGill University.
Critical Path Pro And Cons 2017
Photo Credits
- Polka Dot Images/Polka Dot/Getty Images