SDPM - Lecture 4 - Activity planning and resource allocation

4,189 views

Published on

Published in: Education, Technology, Business
1 Comment
0 Likes
Statistics
Notes
  • Be the first to like this

No Downloads
Views
Total views
4,189
On SlideShare
0
From Embeds
0
Number of Embeds
30
Actions
Shares
0
Downloads
220
Comments
1
Likes
0
Embeds 0
No embeds

No notes for slide

SDPM - Lecture 4 - Activity planning and resource allocation

  1. 1. Leiden Institute of Advanced Computer Science System s Development and Project Management – Activity planning and resource allocation Prof. Dr. Thomas Bäck 1
  2. 2. Leiden Institute of Advanced Computer Science DatesFeb. 1 14:45 – 17:30 Introduction, Project DescriptionFeb. 2 13:45 – 16:30 STEP WISE Approach to Project PlanningFeb. 9 13:10 – 15:45 Selecting an Appropriate Software Dev. ApproachFeb. 15 14:45 – 17:30 Activity Planning and Resource AllocationFeb. 16 15:15 – 18:00 Software Effort EstimationFeb. 22 14:45 – 17:30 Risk management, project escalationFeb. 23 13:45 – 16:30 Project monitoring and controlMar. 1 14:45 – 17:00 ExamMar. 2 13:45 – 16:30 Software Quality AssuranceMar. 8 14:45 – 17:30 Managing People; Contract ManagementMar. 9 13:45 – 16:30 VariousMar. 15 14:45 – 17:30 Trade Fair 2
  3. 3. Leiden Institute of Advanced Computer Science STEP WISE overview 1. Identify project objectives 0. Select Project 2. Identify project infrastructure 3. Analyze pr. characteristics 4. Identify products and activities Review lower level detail 5. Estimate effort for activity For each activity 6. Identify activity risks 10. Lower level planning 7. Allocate resources 9. Execute plan 8. Review / publicize planSystem‘s Development and Project Management - Prof. Dr. Thomas Bäck 3
  4. 4. Leiden Institute of Advanced Computer ScienceSequencing and scheduling objectives !   Time is nature s way of stopping everything happening at once !   Recall… !  The difference between elapsed time and effort !  Examples: baking bread, brewing beer 4
  5. 5. Leiden Institute of Advanced Computer ScienceSequencing and scheduling objectives(cont d) !   Feasibility assessment !  Is the project possible within time and resource constraints? !   Resource allocation !  What are the most effective ways of allocating resources to the project? !   Detailed costing !  When are expenditures likely to take place? !   Motivation !   Co-ordination !  When does staff has to be transferred between projects? 5
  6. 6. Leiden Institute of Advanced Computer ScienceMain stages for sequencing andscheduling 1.  Ideal activity plan: what activities need to be carried out in which order? 2.  Activity risk analysis: aimed at identifying potential (resource) problems 3.  Resource allocation 4.  Schedule production: indicates planned start and completion dates and resources for each activity 6
  7. 7. Leiden Institute of Advanced Computer ScienceIdentifying activities !   Activity-based approach !  Ad-hoc vs. Work Breakdown Structure (WBS) •  WBS may be based on project s products, in turn based on a simple list of final deliverables, and a set of activities required to produce that product. !  May be redefined as project proceeds !   Product-based approach !  Product Breakdown Structure (PBS) !  Product Flow Diagram (PFD) •  Can easily be transformed into ordered list of activities !   Hybrid approach 7
  8. 8. Leiden Institute of Advanced Computer ScienceGraphical representation Do B Activity-on-node Do A Do D Do C Activity-on-arrow Do A Do B Do D Do C 8
  9. 9. Leiden Institute of Advanced Computer ScienceTechniques History !   Originally developed in the 50s !   Critical Path Method (CPM) !   Program Evaluation Review Technique (PERT) !   CPM using Activity-on-Node !   PERT using Activity-on-Arrow !   Alternative: Precedence Networks !  Activity-on-Node !  Links represent precedence or sequencing requirements. 9
  10. 10. Leiden Institute of Advanced Computer ScienceEvents vs. activities events Prepare breakfast Eat breakfast activities !   Event = a point in time (used in activity-on-arrow networks) !  Has no duration !  E.g the start or end of an activity !   Activity = a task or an action with a recognizable start and finish and a duration 10
  11. 11. Leiden Institute of Advanced Computer ScienceRemarks !   No loops in a network! !  Iterations may occur in practice, but cannot be represented !  Solution: Repeat set of activities !   No dangles !  Dangling activities indicate logical errors !  Add a final completion activity as a remedy 11
  12. 12. Leiden Institute of Advanced Computer ScienceNext Step after creation of the Logical Network !   Think about the when … !   CPM primary objectives: !  Planning such that project is completed as early as possible !  Identifying activities likely to affect overall end date !  Dummy activities (dotted lines on a network diagram) •  Zero duration, no resources •  Aid the layout 12
  13. 13. Leiden Institute of Advanced Computer ScienceStart and finish times Latest Earliest start finish activity Latest start Earliest finish ! Activity write report software   ! Earliest start (ES)   ! Earliest finish (EF) = ES + duration   ! Latest finish (LF) = latest task can be completed without   affecting project end; latest start = LF – duration !   Activity span = LF – ES (maximum time allowable for activity) 13
  14. 14. Leiden Institute of Advanced Computer ScienceExample !   Earliest start = day 5 !   Earliest finish = ? !   Latest finish = day 30 !   Latest start = ? !   Duration = 10 days Float = LF - ES - duration What is it in this case? 14
  15. 15. Leiden Institute of Advanced Computer ScienceNotation Activity label Duration ES Activity EF description LS LF Activity span: LF-ES Float: LF-ES-Duration 15
  16. 16. Leiden Institute of Advanced Computer ScienceComplete for previous example A 10 5 Write report 15 20 software 30 25 15 16
  17. 17. Leiden Institute of Advanced Computer ScienceEarliest start date EF = day 7 ES = day10 EF = day10 !   Earliest start date for the current activity = earliest finish date for the previous !   When there is more than one previous activity, take the latest earliest finish !   Note ‘day 7’ = end of work on day 7 17
  18. 18. Leiden Institute of Advanced Computer ScienceExample: ES for activity G? B E Duration 6 Duration 8 A C G Duration 5 Duration 10 F Duration 4 D Duration 3 ES = day 0 Duration 9 18
  19. 19. Leiden Institute of Advanced Computer ScienceComplete the table Activity   ES   D uration   EF   A     0   5   5 B         5 6 11 C     5   10   15 D     5   9   14 E         15 8 23 F     14   3   17 G         23 4 27 19
  20. 20. Leiden Institute of Advanced Computer ScienceLatest start dates !   Start from the last activity !   Latest finish (LF) for last activity = earliest finish (EF) !   Work backwards !   Latest finish for current activity = latest start for the following !   More than one following activity - take the earliest LS !   Latest start (LS) = LF for activity - duration 20
  21. 21. Leiden Institute of Advanced Computer ScienceExample: LS for all activities? B E Duration 6 Duration 8 A C G Duration 5 Duration 10 F Duration 4 D Duration 3 ES = day 0 Duration 9 21
  22. 22. Leiden Institute of Advanced Computer ScienceComplete the table Activity   ES   Dur   EF   L S   L F   A     0   5   5   0   5 B     5   6   11   9   15 C     5   10   15   5   15 D     5   9   14   11   20 E     15   8   23     15 23 F     14   3   17   20   23 G     23   4   27   23   27     22
  23. 23. Leiden Institute of Advanced Computer ScienceFloat Float = Latest finish - earliest start - Image Source: Wikimedia duration FLOAT ES LF activity Latest start 23
  24. 24. Leiden Institute of Advanced Computer ScienceComplete the table LF-ES-Dur Activ.   ES   Dur   EF   L S   L F   Float   A     0   5   5   0   5   0 B               5 6 11 9 15 4 C     5   10   15   5   15   0 D     5   9   14   11   20   6 E     15   8   23       15 23 0 F     14   3   17       6 20 23 G     23   4   27   23   27   0 24
  25. 25. Leiden Institute of Advanced Computer ScienceCritical path: Defines project duration !   Note the path through network with zero floats !   Critical path: any delay in an activity on this path will delay whole project !   Can there be more than one critical path? !   Can there be no critical path? !   Sub-critical paths 25
  26. 26. Leiden Institute of Advanced Computer ScienceTypes of schedules !   Activity schedule - indicating start and completion dates for each activity !   Resource schedule - indicating dates when resources needed + level of resources !   Cost schedule showing accumulative expenditure 26
  27. 27. Leiden Institute of Advanced Computer ScienceResources !   These include !  Labor !  Equipment (e.g. workstations) !  Materials !  Space !  Services !   Time - elapsed time can often be reduced by adding more staff !   Money - used to buy the other resources 27
  28. 28. Leiden Institute of Advanced Computer ScienceResource allocation !   Identify the resources needed for each activity !   Identify resource types - individuals are interchangeable within the group (e.g. VB programmers as opposed to software developers ) !   Allocate resource types to activities and examine the resource histogram 28
  29. 29. Leiden Institute of Advanced Computer ScienceResource histogram: systems analysts 5 Staff required 4 3 2 1 Week 1 2 3 4 5 6 7 29
  30. 30. Leiden Institute of Advanced Computer ScienceResource clashes !   Can be resolved by: !  Delaying one of the activities •  Taking advantage of float to change start date •  Delaying start of one activity until finish of the other activity that resource is being used on - puts back project completion !  Moving resource from a non-critical activity !  Bringing in additional resource - increases costs 30
  31. 31. Leiden Institute of Advanced Computer SciencePriorities !   Critical path activities !   Other activities with little float !   When a short activity would allow a number of larger activities to start 30 days resource 10 days clash 4 days 15 days 15 days 31
  32. 32. Leiden Institute of Advanced Computer ScienceBurman s priority list: Activities that canproceed at same time 1.  Shortest critical activity 2.  Critical activities 3.  Shortest non-critical activity 4.  Non-critical activities with least float 5.  Non-critical activities 32
  33. 33. Leiden Institute of Advanced Computer ScienceResource usage !   Need to maximize percentage usage of resources i.e. reduce idle periods between tasks !   Need to balance costs against early completion date !   Need to allow for contingency !  Scheduling can create new critical paths 33
  34. 34. Leiden Institute of Advanced Computer ScienceCost schedules !   Staff costs: salaries as well as other direct costs of employment !   Overheads: expenditure that organization incurs which cannot be directly related to individual projects !   Usage charge: e.g. processing time Schedule is usually presented on a weekly or cumulative basis 34

×