Unit-3 Activity planning and Scheduling.pptx

SPM unit-3

1. Activity planning and Scheduling Unit - 3

2. Contents: Objectives of activity planning Work breakdown structure Bar chart Network planning model Critical path method(CPM) Program evaluation and review technique(PERT) Precedence diagramming method(PDM) Shortening project duration Identifying critical activities 2

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4. Activity Planning The objective of software project planning is to provide a framework that enables the manager to make reasonable estimates of resources, cost, and schedule. The main objective of activity planning is to provide project and resources schedule. An activity plan should provide a means of evaluating the consequences of not meeting any of the activity target dates and guidance as to how the plan might most effectively be modified to bring the project back to target . 4

5. Objectives of activity planning Feasibility Assessment Resource Allocation Detailed Costing Motivation Coordination 5

6. Objectives of Activity planning: Feasibility Assessment: Is the project possible within required timescales and available resource constraints? Resource Allocation: How effectively the resources can be allocated? How the resources should be made available in time of need? Detailed Costing: How much is the project cost? What is the total expenditure likely to take place? 6

7. Objectives of Activity planning: Motivation : Providing targets and monitoring achievement against targets Coordination : When do the staff in different departments need to be available to work on a particular projects? When do staff need to be transferred between projects? 7

8. When to plan Planning is an ongoing process of refinement, each iteration becoming more detailed and more accurate than the last. During feasibility study and project start up The main purpose of planning will be to estimate timescales and the risks of not achieving target completion dates or keeping within budget. As the project proceeds beyond the feasibility study, the emphasis will be placed upon the production of activity plans for ensuring resource availability and cash flow control. Throughout the project, until the final deliverable has reached the customer, monitoring and re‐planning must continue to correct any drift that might prevent meeting time or cost targets. 8

9. Project Schedule Before work commences on a project, the project plan must be developed to the level of showing dates when each activity should start and finish and when and how much of each resource will be required. One the plan has been refined to this level of detail, we call it a project schedule. Creating a project schedule comprises four main stages The first step :creating an activity plan: deciding which activity to be carried out in which order The second step : activity risk analysis: identifying the potential problems The third step : Resource allocation Last step : schedule production: start and completion dates 9

10. Projects and Activities: Defining activities A project is composed of a number of interrelated activities A project will be completed when all of the activities it encompasses have been completed. An activity must have a clearly defined start and a clearly defined end point. Duration of an activity must be forecastable. Some activities might require that others are completed before they can begin. 10

11. Projects and activities: Identifying activities Essentially there are three approaches to identifying activities that make up a project. Activity based Approach Product based Approach Hybrid approach 11

12. Activity Based Approach Consists of creating a list of all the activities that the project is thought to involve. Might involve a brainstorming session involving the whole project team. While listing activities for a large project, it might be helpful to subdivide the project into subtasks using a Work Breakdown Structure (WB S) Design task has been broken into 3 task and one of them is again decomposed 12

13. The Activity Based approach When preparing a WBS, consideration must be given to the final level of detail or depth of the structure Too great depth will result in a large number of small tasks that will be difficult to manage Too shallow structure will provide insufficient detail for project control. Each branch should, however, be broken down at least to a level where each leaf may be assigned to an individual or responsible section within the organization 13

14. The product based approach Consists of a Product Breakdown Structure (PBS) and a Product Flow Diagram (PFD) The PFD indicates, for each product, which other products are required as inputs. The PFD can easily be transformed into an ordered list of activities. The Product Breakdown Structure (PBS ) is constructed prior to the Work Breakdown Structure and it focuses on generating an ordered list of all the sub products required to successfully complete the project . This generated structure helps in the creation of the Work Breakdown Structure, which in turn helps in the identification of the activities required to produce the required sub products.  14

15. 15 product Deliverable Sub products Sub products

16. The Hybrid Approach In this approach, an alternative work breakdown structure is constructed based on: A simple list of final deliverable. For each deliverable, a set of activities required to produce that product The main problem with the purely activity based work breakdown structure is after identifying all the activities, the task of sequencing them in proper order is always left out. Hence, hybrid approach gives us a modified version of the Work Breakdown Structure which includes some of the important properties of the Product Breakdown Structure and as it includes the important properties of both the approaches, it overcomes the disadvantages of both of them. 16

17. The Hybrid Approach IBM recommended 5 levels in WBS Level 1: Project: Actual project to develop Level 2: Deliverables such as software, manuals and training course Level 3: Components which are the key work items needed to produce deliverables such as the modules and tests required to produce the system software Level 4: Work packages which are major items, or collections of related tasks, required to produce a component Level 5: Tasks which are tasks that will normally be the responsibility of a single person 17

18. Hybrid Approach 18

19. Hybrid Approach 19

20. Sequencing and scheduling activities Throughout a project, we will require a schedule that clearly indicates when each of the project’s activities is planned to occur and what resources it will need. On way of presenting such a plan is to use a bar chart 20

21. Sequencing and scheduling activities 21

22. Network planning model These project scheduling techniques model the projects activities and their relationships as a network. In a network, time flows from left to right. The two best known models are : CPM ( Critical Path Method) PERT (Program Evaluation Review Technique) Both CPM and PERT provide the user with project management tools to plan, monitor and update their project as it progresses. 22

23. Similarities between PERT and CPM Both of these techniques used an activity -on-arrow approach to visualizing the project as a network where activities are drawn as arrows joining circles, or nodes which represent the possible start and /or completion of an activity or set of activities. They can be used to determine the earliest/latest start and finish times for each activity. 23

24. Differences between PERT and CPM More recently variation of these techniques, called precedence network, has become popular. This method uses activity-on-node networks where activities are represented as nodes and the links between nodes represent sequencing requirements. In CPM, estimates of activity duration are based on historical data • In PERT, estimates are uncertain and we talk of ranges of duration and the probability that an activity duration will fall into that range • In routine projects where estimated time for each activity is known, CPM is a better tool to control both time and cost. 24

25. Formulating a network model The first stage in creating a network model is to represent the activities and their interrelationships as a graph To construct a network model following rules should be followed: A project network should have only one start node A project network should have only one end node A node has duration 25

26. Formulating a network model: Rules Links normally have no duration Precedents are the immediate preceding activities Time moves from left to right A network may not contain loops A network should not contain dangles 26

27. Formulating a network model: Rules A project network should have only one start node: Using more than one starting node is a source of confusion so, only one start node is preferred A project network should have only one end node: A project may only finish once so one end node is preferred. A node has duration: Node refers to one activity of the project so it takes some fixed amount of time to execute. 27

28. Formulating a network model: Rules Links normally have no duration: Links normally represent the relationship or flow of the activities Precedents are the immediate preceding activities: Activity 4 cannot be started until 2 and 3 are not completed 28

29. Formulating a network model: Rules Time moves from left to right: A network may not contain loops : A loop is an error in that it represents a situation that cannot occur in practice 29

30. Formulating a network model: Rules A network should not contain dangles: Documentation or writing user manual like things should not be mentioned in the network model 30

31. Critical Path Method (CPM) Critical path method is the sequential activities from start to the end of a project. Although many projects have only one critical path, some project may have more than one critical paths. Techniques used in the CPM are: A list of activities required to complete the project The time or duration that each activity will take to completion. The dependencies between the activities. 31

32. Critical Path Method (CPM) 32

33. Critical Path Method (CPM) 33

34. 34 Arrow plays an important role in determining the flow of the activities

35. Critical Path Method (CPM) 35 Square or circle denotes the activity and value in arrow denotes the duration of the activity.

36. Forward pass and Backward pass Forward Pass: Take the highest value in case of two predecessor. 36 A – H = Activity Duration: 5,7,4,10,3,5,6,4 In case of D and E to G only highest value will be taken In case of G and F to H only highest value will be taken Project Duration = 32

37. Forward pass and Backward pass Earliest First(ES) : Earliest finish(EF) = ES + D Slack Time = LF – EF Latest start = LF – duration Critical path is the one in which the slack time For all activity must be zero. For first activity ES is always zero and for succesors , ES will be the EF of previous activity. For the end point LF will be same as EF. On moving towards left LF will be the LS of the successor. 37 ES EF LS LF

38. Forward pass and Backward pass Back ward Pass: In case of backward pass start from the end node or project duration and move backward and keep on doing difference. In case of two successor connecting to an activity do the difference and choose the smallest value. 38

39. Forward pass and Backward pass 39

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41. Forward pass and Backward pass 41

42. Example: Critical Path Method Determine the critical path, the critical activities and the project completion time. 42

43. Example: Critical Path Method Network diagram 43

44. Example: Critical Path Method 44 Compare the times for the two paths. Maximum of {22,19} = 22. We see that path I has the maximum time of 22 weeks. Therefore, path I is the critical path. The critical activities are A, B, D and F. The project completion time is 22 weeks.

45. PERT Program evaluation and Review technique (PERT) is a project management tool used to schedule, organize and coordinate tasks within a project. It is basically a method to analyze the tasks involved 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. Main objective of PERT is to facilitate decision making and to reduce both the time and cost required to complete a project. 45

46. THANK YOU 46