Critical path method PDF

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Critical path method...

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Critical Path Method (CPM)/Program Evaluation and Review Technique (PERT)

Introduction The network-based analysis enables design and planning of a project, at all levels of details, regarding the duration of each activity, the order of priority, the review of the program when changes or delays happen and finally the cost of the project. The methods of network-based analysis which are used to optimize the design and planning of a project are Program Evaluation and Review Technique (PERT) and Critical Path Method (CPM) . These methodologies were developed independently of each other in late 50s. Researchers have used PERT method for handling problems with stochastic activities time (randomly determined process, term stochastic is used in many different fields, particularly where stochastic or random processes are used to represent systems or phenomena that seem to change in a random way.) while they have used CPM for problems with deterministic times.(deterministic system is a system in which no randomness is involved in the development of future states of the system. A deterministic model will thus always produce the same output from a given starting condition or initial state.)

Essentially, this difference resulted because these two methods encountered problems of different nature during the period they were developed. There were also differences in the way in which the two methods depicting activities with a network form. In PERT networks, the activities were represented with edges while in CPM networks, the nodes symbolized the activities. In any case, these differences do not exist anymore. The way of representation of the activities is based on the user's selection while the methodology is merged in a common method which is called PERT/CPM method. According to this, all the networks which are obtained by this method, they are called PERT/CPM networks. The critical path method (CPM), or critical path analysis (CPA), is an algorithm for scheduling a set of project activities. It is commonly used in conjunction with the program evaluation and review technique (PERT). A critical path is determined by identifying the longest stretch of dependent activities and measuring the time required to complete them from start to finish. Critical Path Analysis is commonly used with all forms of projects, including construction, aerospace and defense, software development, research projects, product development, engineering, and plant maintenance, among others. Any project with interdependent activities can apply this method of mathematical analysis

Advantages of Critical Path Method (CPM): It has the following advantages:

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It figures out the activities which can run parallel to each other.

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It helps the project manager in identifying the most critical elements of the project.

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It gives a practical and disciplined base which helps in determining how to reach the objectives.

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CPM is effective in new project management.

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CPM can strengthen a team perception if it is applied properly.

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CPM provides demonstration of dependencies which helps in the scheduling of individual activities.

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It shows the activities and their outcomes as a network diagram.

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It gives a fair and concise procedure of documenting of project.

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It helps in determining the slack time.

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An explicit and clear approach of communicating project plans, schedules, time and cost performance is developed.

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It is extensively used in industry.

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It helps in optimization by determining the project duration.

Disadvantages of Critical Path Method (CPM): It has the following disadvantages: 1.

The scheduling of personnel is not handled by the CPM.

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In CPM, it is difficult to estimate the completion time of an activity.

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The critical path is not always clear in CPM.

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For bigger projects, CPM networks can be complicated too.

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It also does not handle the scheduling of the resource allocation.

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In CPM, critical path needs to be calculated precisely....