1 / 20

PERT Charts

PERT Charts. Prepared by: Michael Palazzo. What are PERT Charts?. PERT stands for Program Evaluation and Review Technique To understand what a PERT chart is, we must first learn the Critical Path Method (CPM). CPM. D eveloped as a network model for project management

tibor
Download Presentation

PERT Charts

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. PERT Charts Prepared by: Michael Palazzo

  2. What are PERT Charts? • PERT stands for Program Evaluation and Review Technique • To understand what a PERT chart is, we must first learn the Critical Path Method (CPM)

  3. CPM • Developed as a network model for project management • Uses a fixed time estimate for each activity • Easy to understand but does not account for time variations of activities

  4. What is PERT? • Developed in late 1950’s • A network model that allows for randomness in activity completion times • Has potential to reduce time and cost to complete a project

  5. Network Diagrams • PERT Charts use network diagrams • Activities and milestones of a project are represented by arcs and nodes on a model • PERT was originally Activity-on-Arc diagram • Some now use Activity-on-Node

  6. Arc vs. Node Activity-on-node network: Activity-on-arc network:

  7. Example of a PERT Chart

  8. 6 Steps • Identify • Determine Activity Sequence • Construct • Estimate • Determine Critical Path • Update

  9. Identify/Determine Activity Sequence • Identify Activities and Milestones: • Activities are tasks • Milestones mark beginning and end of activities • Determine Activity Sequence: • Sequence is evident for some • Others require more analysis

  10. Construct • Construct the Network Diagram: • Create diagram with activity sequence info • For activity-on-arc model, activities are arrowed lines and milestones are circles • Software exists to simplify this step

  11. Estimate • Estimate Activity Times: • Weeks are commonly used as unit of time • PERT is able to deal with uncertainty in activity completion times • Each activity in model includes three time estimates

  12. Estimate Continued… • Optimistic Time: • Shortest time activity can be completed • Most Likely Time: • Completion time with highest probability • Pessimistic Time: • Longest time the activity might require

  13. Determine Critical Path • Critical path is longest path in project • Determined by adding the times for activities in each sequence • By accelerating activities on critical path you decrease total project time

  14. Update • Update as Project Progresses: • Make adjustments to PERT chart as project continues • Resources may need to be added to stay on schedule if there are delays

  15. Benefits of PERT • Gives expected project completion time • Provides probability of completionbefore a date • Shows critical path activities

  16. Benefits Continued… • Provides activity start and end dates • Shows activities that have slack time

  17. Limitations of PERT • The activity time estimates are subjective • PERT assumes a beta distribution for its time estimates; actual distribution may be different

  18. Limitations Continued… • Consistently underestimates the expected project completion time • PERT assumes probability distribution of project completion time is same as critical path • If delayed, other paths can become critical path

  19. References • Pert Charts:http://www.netmba.com/operations/project/pert/ • More Information on CPM/CPA:http://www.mindtools.com/critpath.html • PERT Chart Images:http://en.wikipedia.org/wiki/Program_Evaluation_and_Review_Techniquehttp://cpmtutor.com/c05/fp-dummies.htmlhttp://cnx.org/content/m32170/latest/

  20. Thank you for your attention!

More Related