Question

The table below gives the optimistic, most-likely, and pessimistic time estimates (in weeks) for all activities in a project. (Statistical tables are available in appendix I) Activ Predecessor totm t 2.0 5.0 8.0 3.0 4.0 5.0 4.06.08.0 5.0 6.0 7.0 3.0 6.0 9.0 D, E (i) Calculate the estimated time and variance for each task (ii) Draw the AON diagram and identify the critical path. (iii) What is the expected critical path duration and estimate a standard deviation for the path.

Answer 1

PERT refers to Program evaluation and review technique where networks are used to plan and control the project and CPM refers to critical path method where shortest path is taken to plan the project. The objectives of PERT/ CPM are: -

• Plan is made visually that help the project team to understand the progress and direction.
• Project completion time can be determined.
• Brainstorming what needs to be done.
• To identify the task that require tight control.
• To identify task that is critical for completion time.

s0l EF= ES+ duraton LE mininmers (iet | LS- LE-duration LF- EF LS -S

Ce 24 0 4.0 Et 2.0 + (4 x 2-0 + 2.0 a 30 :3°0+ 16 0 5 0 う6-0 6 .0

36 O 6 *0 3240 t90 36 0 6 '0 2. 30-20 6.0

6 10.44 2012 0

PagelWork S:O Date: The path cal eniral pak dael e 1a 6 6 0 6 6 0 33 2-0 Standard duialeec e 03333