Quest Write Short notes on: 1. PERT model 2. CPM model Answer: PERT Model: PERT, Program (or project) evaluation and review technique is a method to analyse the involved tasks in completing a given project, especially the time needed to complete each task, and to identify the minimum time needed to complete the total project. PERT was developed primarily to simplify the planning and scheduling of large and complex projects. It was developed for the U.S. Navy Special Projects Office to support the U.S. Navy's Polaris nuclear submarine project. It was able to incorporate uncertainty by making it possible to schedule a project while not knowing precisely the details and duration of all the activities. It is more of an event-oriented technique rather than start- and completion- oriented, and is used more in projects where time is the major factor rather than cost. It is applied to very large-scale, one-time, complex, non- routine infrastructure and Research and Development projects. PERT chart explicitly defines and makes visible dependencies (precedence relationships) between the work breakdown structure (commonly WBS) elements. It facilitates identification of the critical path and makes this visible also identification of early start, late start, and slack for each activity. It provides for potentially reduced project duration due to better understanding of dependencies leading to improved overlapping of activities and tasks where feasible. CPM Model: The critical path method (CPM) is a step-by-step project management technique for process planning that defines critical and non-critical tasks with the goal of preventing time-frame problems and process bottlenecks. The CPM was developed in the 1950s by DuPont, and was first used in missile-defence construction projects. CPM is ideally suited to projects consisting of numerous activities that interact in a complex manner. In applying the CPM, there are several steps that can be, defining the required tasks and putting them down in an ordered (sequenced) list, creating a flowchart or other diagram showing each task in relation to the others, identifying the critical and non-critical relationships (paths) among tasks, determining the expected completion or execution time for each task, locating or devising alternatives (backups) for the most critical paths. CPM is commonly used with all forms of projects, including construction, aerospace and defence, software development, research projects, product development, engineering, and plant maintenance, among others. Any project with interdependent activities can apply this method of mathematical analysis. Although the original CPM program and approach is no longer used, the term is generally applied to any approach used to analyse a project network logic diagram.