5 6 representing the proper sequencing. PERT basically does not demarcate CPM marks the critical activities. between critical and non-critical activities. PERT is applied in projects where CPM is applied to projects where minimum resources are always made available. overall cost is the prime importance. PERT is suitable in Defence project and Suitable for plant maintenance, civil R&D where activity time can't be readily construction projects etc. where activity predicted. duration is known. 7 Steps in using network techniques 1. Plan of project x23 (a) The project is analyzed by determining all the individual activities (sometimes called tasks/jobs/operation) that must be performed to complete it. (b) A planned sequence of these activities are shown on a network (a graph where arrow and circles represent the relationship among project activities) 2. Schedule of project (a) How long it will take to perform each activity is estimated. (b) In order to locate the critical path, calculation is performed (the longest time chain of sequential activities which determines the duration of project). This step also provides other information that is useful in scheduling, (c) The above information are used to develop a more economical and efficient schedule. 3. Project monitoring (a) The plan and schedule started above are used to monitor the progress. (b) Throughout the execution of project, the schedule is revised and updated so that the schedule represents the current plan and status of progress. (c) PERT, Critical path, Most likely time estimates. The above points can be explained with the following examples. Ex: 1 A project consists of the following activities and time estimates. Activity 1-2 1-3 1-4 2-5 2-6 3-6 4-7 5-7 6-7 Least time (to) in days 3 2 6 2 5 3 3 1 2 Greatest time (t) in days 15 14 30 8 17 15 27 7 8 Most likely time (tm) in days 6 5 12 5 11 6 9 4 5 Construct the network. Determine the expected task time and the critical path