1 / 34

Network Scheduling: Effective Project Time Management

Learn about network scheduling techniques like CPM, PERT, and GERT to convert project action plans into operating timetables. Understand how to identify critical activities, determine start dates, and ensure proper communication for successful project completion.

weaverl
Download Presentation

Network Scheduling: Effective Project Time Management

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 8 Scheduling

  2. Useful Abbreviations • CPM - Critical Path Method • GERT - Graphical Evaluation and Review Technique • PERT - Program Evaluation and Review Technique

  3. Background • Schedule is the conversion of a project action plan into an operating timetable • Basis for monitoring project • One of the major project management tools • Work changes daily so a detailed plan is essential • Not all activities on a project need to be scheduled to the same level of detail

  4. Background Continued • Most scheduling is at the WBS level, not the work package level • Only the most critical work packages may be shown on schedule • Most scheduling is based on network drawings

  5. Network Scheduling Advantage • Consistent framework • Shows interdependences • Shows when resources are needed • Ensures proper communication • Determines expected completion date • Identifies critical activities

  6. Network Scheduling Advantage Continued • Shows which activities can be delayed • Determines start dates • Shows which tasks must be coordinated • Shows which tasks can run in parallel • Relieves some conflict • Allow probabilistic estimates

  7. Network Scheduling Techniques • Developed 1958 – 1959 for Polaris missile/submarine project • Initially, CPM and PERT were two different approaches • CPM used deterministic time estimates and allowed project crunching • PERT used probabilistic time estimates • Microsoft Project (and others) have blended CPM and PERT into one approach

  8. Terminology • Activity - A specific task or set of tasks that are required by the project, use up resources, and take time to complete • Event - The result of completing one or more activities • Network - The combination of all activities and events that define a project • Drawn left-to-right • Connections represent predecessors

  9. Terminology Continued • Path - A series of connected activities • Critical - An activity, event, or path which, if delayed, will delay the completion of the project • Critical Path - The path through the project where, if any activity is delayed, the project is delayed • There is always a critical path • There can be more than one critical path

  10. Terminology Continued • Sequential Activities - One activity must be completed before the next one can begin • Parallel Activities - The activities can take place at the same time • Immediate Predecessor - That activity that must be completed just before a particular activity can begin

  11. Terminology Continued • Activity on Arrow - Arrows represent activities while nodes stand for events • Activity on Node - Nodes stand for events and arrows show precedence

  12. AON and AOA Format Figure 8-2 Figure 8-3

  13. Constructing the Network (AON Version) • Begin with START activity • Add activities without precedences • There will always be one • May be more • Add activities that have those activities as precedences • Continue

  14. Gantt Charts • Developed by Henry L. Gantt • Shows planned and actual progress • Easy-to-read method to show current status

  15. Advantages and Disadvantages • Easily understood • Provide a picture of the current state of a project • Difficult to follow with complex projects

  16. Microsoft Project Gantt Chart Figure 8-11

  17. Microsoft Project AON Network Figure 8-12

  18. Solving the Network Table 8-1

  19. The AON Network Figure 8-14

  20. Calculating Activity Times

  21. The Results Table 8-2

  22. Critical Path and Time Figure 8-15

  23. Critical Path and Time Continued Figure 8-16

  24. Slack Figure 8-16

  25. Slack Values Table 8-3

  26. Precedence Diagramming • Finish to start • Start to start • Finish to finish • Start to finish

  27. Precedence Diagramming Conventions Figure 8-17

  28. Microsoft Projects Table 8-4

  29. Gantt Chart Figure 8-18

  30. AON Network Figure 8-19

  31. Microsoft Project Calendar Figure 8-23

  32. Uncertainty of Project Completion Time • Assume activities are statistically independent • Variance of a set of activities is the sum of the individual variances • Interested in variances along critical path

  33. Example

  34. Toward Realistic Time Estimates • Calculations are based on 1% chance of beating estimates • Calculations can also be based on 5% or 10% • Changing the percentage requires changing the formulae for the variance • When using 5%, the divisor changes to 3.29 • When using 10%, the divisor changes to 2.56

More Related