Program evaluation and review technique: Difference between revisions

Revision as of 12:34, 20 March 2023

Revision as of 22:50, 1 June 2023

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=== Time ===

PERT has defined four types of time required to accomplish an activity:

* ''optimistic time'': the minimum possible time required to accomplish an activity (o) or a path (O), assuming everything proceeds better than is normally expected<ref>{{cite book | author = Kerzner, Harold | year = 2009 | title = Project Management: A Systems Approach to Planning, Scheduling, and Controlling |edition = 10th | publisher = Wiley | isbn = 978-0-470-27870-3| author-link = Harold Kerzner }}</ref>{{rp|512}}

* ''pessimistic time'': the maximum possible time required to accomplish an activity (p) or a path (P), assuming everything goes wrong (but excluding major catastrophes).<ref>{{cite book | author = Kerzner, Harold | year = 2009 | title = Project Management: A Systems Approach to Planning, Scheduling, and Controlling |edition = 10th | publisher = Wiley | isbn = 978-0-470-27870-3| author-link = Harold Kerzner }}</ref>{{rp|512}}

* ''most likely time'': the best estimate of the time required to accomplish an activity (m) or a path (M), assuming everything proceeds as normal.<ref>{{cite book | author = Kerzner, Harold | year = 2009 | title = Project Management: A Systems Approach to Planning, Scheduling, and Controlling |edition = 10th | publisher = Wiley | isbn = 978-0-470-27870-3| author-link = Harold Kerzner }}</ref>{{rp|512}}

* ''expected time'': the best estimate of the time required to accomplish an activity (te) or a path (TE), accounting for the fact that things don't always proceed as normal (the implication being that the expected time is the average time the task would require if the task were repeated on a number of occasions over an extended period of time).<ref>{{cite book | author = Kerzner, Harold | year = 2009 | title = Project Management: A Systems Approach to Planning, Scheduling, and Controlling |edition = 10th | publisher = Wiley | isbn = 978-0-470-27870-3| author-link = Harold Kerzner }}</ref>{{rp|512-513}}

::: <math> te = \frac{o + 4m + p} 6 </math>

:::<math>TE = \sum_{i=1}^n te_i</math>