Programme Evaluation and Review Technique

The slides explain the concept of Programme Evaluation and Review Technique and Critical Path Method

1. Application of the concepts ' Programme Evaluation and Review Technique' (PERT) and 'Critical Path Method’ (CPM) in dairy enterprise: A Network Analysis perspective Dr. Asif Mohammad Senior Scientist ICAR-National Dairy Research Institute Kalynai-741235, West Bengal

2. Planning is the most important stage of project management ' Programme Evaluation and Review Technique' (PERT) and 'Critical Path Method’ (CPM) are very important project management concept applied for planning and controlling the timeline M.R.Walker of E.I.Du Pont de Nemours & Co. and J.E.Kelly of Remington Rand invented CPM (Critical Path Method) in 1957. PERT (Project Evaluation and Review Technique) was developed by the Program Evaluation Branch of the US Navy's Special Projects office in 1958 Introduction

3. Concept associated with network analysis Arrows → An arrow pointing from the tail to the head indicates activity, which is a time-consuming effort required to complete a task. Nodes : A circle is used to represent a node that depict an EVENT, which is a moment when one or more actions begin and/or end. An arrow represents an activity, which is a task or a specific amount of work that must be completed as part of the project . Dummy Activity identifies just precedence relationships and does not necessitate any effort on the part of the user. The beginning or finish of an activity is signaled by an event, which designates a moment in time and is represented by a circle (node)

4. PERT planning process I. Identifying the activities and events that will take place II. Establishing the order of activities III. Construction of the network diagram IV. Estimation of the duration of an activity V. Identification of the critical path VI. Continual updating as the project progresses

5. I. Identifying the activities and events that will take place The activities are the actions that must be completed in order to the project to be completed effectively. The events serve as markers, indicating the start and finish of one or more activities. Listings of the tasks in a table that can be expanded in later steps to include information on sequence and duration is the first step in PERT planning process.

6. II. Establishing the order of activities As the activity sequence is obvious for some tasks, this phase can be integrated with the activity identification stage. Other tasks may necessitate further investigation to identify the precise order in which they should be completed.

7. III. Construction of the network diagram A network diagram can be built using the activity sequence information to depict the succession of serial and parallel activities. The arrow indicates activities, whereas the circle indicates occurrences. There are software applications available to draw tabular data into a network diagram.

8. IV. Estimation of the duration of an activity Weeks are a common unit of time for completing tasks. PERT's capacity to deal with uncertainty in activity completion timeframes is one of its distinctive features. The model normally includes three time estimates for each activity: • Optimistic time - This is the smallest amount of time in which an activity can be performed. • Most likely completion time – This is the most likely completion time. Most likely time is not similar to expected time. • Pessimistic time - This is the longest amount of time to finish a task.

9. For the time estimates, PERT assumes a beta probability distribution. The expected time for each action in a beta distribution can be computed using the following formula: (Optimistic + 4 x Most Likely+ Pessimistic) / 6 = Expected Time This expected time is typically depicted in a network diagram. The following formula is used to calculate the variance for each activity completion time: [(Pessimistic - Optimistic) / 6] 2

10. V. Identification of the critical path The critical path is determined by adding the timings for the activities in each sequence of activities and determining the longest path in the project. ES - Earliest Starting Time: The earliest time at which an activity can begin provided that the activity before it has previously been completed. EF - Earliest Finish Time: This is the sum of the earliest start time and the time needed to complete the activity. LS - Latest Start Time: This time is equal to the most recent finish time minus the amount of time required to complete the activity. LF - Latest Finish Time: The latest time is the shortest amount of time within which the activity can be completed without causing the project to be delayed.

11. VI. Continual updating as the project progresses The PERT chart can be adjusted based on the project's progress. Actual time replaces expected time and the PERT chart is adjusted accordingly.

12. Common concepts for construction of project network

13. Some rules of drawing network Rule 1: In the network, each activity is represented by one and only one arrow. Rule 2: The same end events cannot be used to identify two activities.

14. Name of the activity Activity( i , j) Normal Time ( N ij ) Earliest Time Latest Time Float Time (L i - N ij )- E i Start ( E i ) Finish ( E i + N ij ) Start (L i - N ij ) Finish (L i ) Forming farmers group (1, 2) 2 2 5 7 5 Getting training (1, 3) 2 2 2 Purchasing animals (1, 4) 1 1 6 7 6 Ensuring clean milk production (2, 6) 4 2 6 7 11 5 Procuring high yielding animals (3, 7) 5 2 7 3 8 1 Procuring animals and machinery (3, 5) 8 2 10 2 10 Machinery purchase (4, 5) 3 1 4 7 10 6 Promoting brand (5, 9) 5 10 15 10 15 Procuring utensils (6, 8) 1 6 7 11 12 5 Procuring milk (7, 8) 4 7 11 8 12 1 Processing milk (8, 9) 3 11 14 12 15 1

15. PERT's Advantages Project completion deadline Increased probability of completing the task before the deadline The activities in the critical path that have a direct impact on the completion time Identification of those tasks that allow for slack time and that can lend resources to critical path Dates of the Activity's start and end Efficient tool for project management Monitoring of costs in a project is possible

16. PERT's Limitations The activity time estimations are not entirely objective and are based on the manager's assessment. For the time estimates of different activities in the network, PERT assumes a beta distribution, although in real life, it may be a different sort of distribution. I n the actual world, some activities that are not on the critical path may become critical as a result of the delays in other activities.

17. Advantage of CPM CPM creates a graphical representation of the project in the form of a network, which aids in estimating the amount of time it will take to complete the project. It also identifies the activities that are necessary to accomplish the project within the allotted time limit.

18. Limitations of CPM CPM can be used to manage both routine and complex tasks. When a project is less conventional and changes to the expected completion time are required virtually every day, finding the actual completion time becomes quite challenging.

19. Conclusion PERT and CPM are both time-oriented methodologies in the sense that they both result in the creation of a project schedule . The major distinction between the two systems is that in CPM, time estimates for various activities were thought to be deterministic, whereas in PERT, time estimates are described probabilistically. In the dairy farming activities where the tasks are repetitive in nature and the costs and time estimate becomes uncertain. Network analysis can give better understandings of the situation and can help in effective planning so that the scarce resources (both time and money) can be utilized in most efficient way.

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