PERT processes data that represent significant events in a project through the use of a computer. Also, it estimates the time of completing an activity and the start of the successive activity. As such, it gives an estimate of the earliest and latest finishing of an activity and the maximum resources that should be allocated to any critical activity. PERT assists in monitoring and controlling a projects activities by determining the maximum and minimum time and resources to assign to a project. When these limits are exceeded, it signifies that there is a problem with the project that needs to be corrected.
Like all other processes, PERT has its advantages and disadvantages. The advantages of using PERT include its ability to show dependency among activities. Additionally, PERT makes visible the critical activities and earliest and latest finish and start time of a critical event. Moreover, a projects duration is also reduced due to the elimination of overlapping of activities and organization of the projects data. The disadvantages include. possibility of numerous activities and dependency of individual projects. It is also unsuitable for small projects, and lastly there is a lack of a timeframe on the technique’s charts makes it difficult to show a project’s status.
Critical path method (CPM) was designed by Morgan R. Walker and James Kelly in 1950s. CPM is an algorithm that schedules a set of the activities of a project. The basic technique involves the construction of a projects model, that contains all the activities needed to complete the project, time required for each activity, dependency relationship of events, and logical points such as deliverables and milestones. These values are used to calculate the longest path of the planned activities. The earliest and latest starting and finishing line of the activities along the critical path are also determined.