PERT (Program Evaluation and Review Technique) is a most commonly used project management method which was developed in connection with a Research and Development (R&D) work. Therefore, it had to cope with the uncertainties that are associated with R&D activities. In PERT, the total project duration is regarded as a random variable. Therefore, associated probabilities are calculated in order to characterize it.
CPM (Critical Path Method) is a project planning method developed mainly in connection with a construction project, which consisted of routine tasks whose resource requirements and duration were known with certainty. Therefore, it is basically deterministic.
PERT
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CPM
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- Used mainly in R&D works where projects carry uncertainties.
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- Mostly used in construction related projects where tasks are repetitive and routine.
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- Total project duration are taken as random variables and can not be estimated easily.
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- Total project duration can be estimated with certainty since activities involves routine tasks.
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- This method mainly uses event oriented network.
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- This method mostly uses activity oriented network.
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- A Probabilistic model is used in this method.
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- A Deterministic model is used in this planning method.
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- It is tool for planning and controlling of cost and time is difficult to achieve because of probabilistic nature.
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- This method can achieve of controlling both cost and time.
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- In this model to minimize the cost time management is of prime importance. Here cost depends directly with time and hence project duration (time) becomes the controlling factor.
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- In this method project completion time is depended on controlling cost by cost optimizing. Here cost does not vary in direct proportion to time. Hence project cost becomes the controlling factor.
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