Chapter 6: Activity planning (3708)

Chapter 6: Activity planning (3708)

1. Introduction

   • Project plan must include a schedule for start and end times of each activity
     • Ensures resource availability
     • Avoid activities competing for resources
     • indicate which staff does which activity
     • Produce baseline to measure actual against
     • Cash flow forecast
     • Replan project to correct drift from target
   • Activity plan provides a target start and end date for each activity
   • Try have each activity produce a deliverable product or tangible outcome

2. 6.2 Objectives of activity plan

   • Feasibility assessment
     • Chapter 5 -> is the project possible in time frame and resource constraints
   • Resource allocation
     • Most effective resource allocation to the project
   • Detailed costing
     • How much will project cost and when is the expense incurred
   • Motivation
     • Providing targets. Monitoring actuals against targets
   • Co-ordination SPM (5e)
     • Coordinating different staff to be available for work
   • Completing the project at a minimum time at an acceptable cost
   • Indicate the implications on the time scale by adding constraints -> such as quality requirements
   • Planning continues at each stage from the beginning to product delivery

3. 6.4 Project schedules

   • Project plan must indicate start and end dates and resources -> It then becomes a project schedule
   • Start with a ideal activity plan -> no constraints on resources
   • Ideal activity plan -> Step 6 identifies the risks of activity
   • Step 7 -> resource allocation -> might affect ideal plan as there is no resource constraints -> ideal plan might need to be adapted to include resource availability
   • Step 8 -> Schedule production -> Start and end dates of activities and resource allocations

4. 6.5 Projects and activities

   • Defining Project
     • Interrelated activities
     • Starts when at least one activity can begin
     • Complete when all activities complete
     • Activity has start and end and defines a deliverable
     • Activity requires resources
     • Duration of activity must be forecastable
     • Activities may be dependent on one another
   • Identify activities
     • activity based approach
       • Create list of all activities in project
       • Use brainstorming
       • Generate a WBS which identifies the high level tasks
         • Each WBS branch has activities which collectively complete the WBS nodes
         • Advantages -> Likely for tasks catalogue to be complete, and non-overlapping activities
         • Only the leaves are activities
       • Figure 1: A fragment of an activity-based work breakdown structure
     • product based approach
       • Chapter 2
         • Product Breakdown Structure (PBS) and a Product Flow Diagram (PFD)
         • PFD -> Which other products are required as inputs for other product
           • PFD can be transformed to list of activities by determining transformations of one product to the other
         • Advantage - > Less likely a product is omitted from PBS
         • Useful for methodologies -> SSADM and USDP
       • Figure 2: product based approach
     • hybrid approach
       • Hybrid Approach based on deliverables and activities
       • 5 levels of WBS according to IBM
         • Level 1 -> Project
         • Level 2 - > Deliverables such as software, manuals and training course
         • Level 3 -> Components -> key work items needed to produce deliverables
         • Level 4 -> Work packages ->major work items or collections of related tasks
         • Level 5 -> Tasks normally for a single person

5. 6.6 Sequencing and scheduling activities

   • Sequence activities based on logical relationships
   • Schedule activities -> taking into account resources

6. 6.7 Network planning models

   • Scheduling technique -> models activities and relationships as a network
   • Network's time flows left to right
   • Best know techniques in this area -> Critical Path Method (CPM) and Program Evaluation Review Technique (PERT)
     • Both use activity on arrow approach to visualise project as network
     • Activities are drawn as arrows
     • Arrows join circles -> circles are start and/or end end of activity or set of activities
   • A variation of technique is -> precedence network
     • Method -> Activity on node networks
     • Activities -> are nodes
     • Links between nodes -> precedence (sequencing)

7. 6.8 Formulating a network model

   • Network has one start node
   • Network has one end node
   • Each activity has a time
   • Nodes have not execution time
   • Flow from left to right
   • Nodes are numbered
   • Loop free network
   • Dangle free network
   • how to representing lagged activities
     • Staggered activities in parallel
     • Lag is represented on the linking arrow in days -> when it starts and when it ends
   • Hammock activities -> have zero duration
     • Start with first hammocked activity and ends with last
     • Can represent over head costs or resources used at constant over actvities
   • Labeling conventions

8. 6.9 Adding the time dimension

   • When dependencies are identified and the logical network model is drawn
   • CPM -> concerned with completing the project ASAP and Identifying the activities which will cause a delay (critical path)
   • Each activity requires a duration
   • Forward pass -> calc earliest dates activities can commence and be completed
     • If actual start date known -> can use actual dates, otherwise use days/weeks
     • Activities start at the end of week 0 or begin of week 1 (same thing)
     • Activity A, B and F can start immediately
     • A -> 6 weeks, earliest finish is 6 weeks
     • B -> 4 weeks, earliest 4 weeks, and for F -> 10 weeks
     • C -> earliest start is 6 weeks, earliest finish is week 9
     • E, H and G can start after its longest dependency
   • Backward pass -> calc latest dates activities can start and the critical path
     • We assume that latest completion date is same as earliest completion date
     • Completion for G and H is week 13
     • H -> latest start week 11 (13-2)
     • G -> Latest start week 10 (13-3)
     • C -> Latest completion is start of H
     • E and F -> latest end is week 10
   • Identify the critical path
     • One path of successive activities which define duration of project
     • Activity float (middle number)-> Difference between activity earliest start and latest start or earliest finish and latest finish
     • When the float is zero it is on the critical path
     • Activity span -> maximum allowed time for activity
       • Difference between earliest start and latest end

9. 6.13 Activity float

   • Measures of activity float
     • Free float -> Activity may be delayed by time frame which doesn't affect other sub activities
       • Difference between earliest completion date and earliest start of subsequent activity
     • Interfering float -> Difference between total float and free float
       • Once free float is used or zero this float tells us how much activity can be delayed without delaying project end date, but delay the start dates of subs
   • Don't issue total float as Activity A using 2 weeks float, leaves activity B with no float. hence critical path time

10. 6.14 Shorter project duration

    • Add resources, reduce the critical path durations

11. Activity on Arrow networks

    • Same rules as network nodel
    • Dummy activities
      • When two paths have a common dependency but are in other aspect mutually exclusive
    • Lagged activities
      • Have to use pairs of dummy activities
    • Labelling

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