Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall o P.I.I.M.T o American University of Leadership Ahmed Hanane, MBA, Eng, CMA, Partner

Project Scheduling: Networks, Duration Estimation, and Critical Path 09-02

After completing this chapter, students will be able to: Understand and apply key scheduling terminology. Apply the logic used to create activity networks, including predecessor and successor tasks. Develop an activity network using Activity-on- Node (AON) techniques. Perform activity duration estimation based on the use of probabilistic estimating techniques

After completing this chapter, students will be able to: Construct the critical path for a project schedule network using forward and backward passes. Identify activity float and the manner in which it is determined. Calculate the probability of a project finishing on time under PERT estimates. Understand the steps that can be employed to reduce the critical path

FIGURE 9.1 Johannesburg Soccer City Stadium Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall

Project scheduling requires us to follow some carefully laid-out steps, in order, for the schedule to take shape. Project planning, as it relates to the scheduling process, has been defined by the PMBoK as: The identification of the project objectives and the ordered activity necessary to complete the project including the identification of resource types and quantities required to carry out each activity or task

o Successors o Predecessors o Network diagram o Serial activities o Concurrent activities E D C B A F 09-07

E D C B A F Merge activities Burst activities Node Path Critical Path 09-08

FIGURE 9.2 Alternative Activity Networks for Term Paper Assignment Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 09-09

The same mini-project is shown with activities on arc… C E D B F E C D B F …and activities on node

Early Start Activity Float Activity Descriptor Late Start ID Number Activity DurationLate Finish Early Finish 09-11

FIGURE Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall

FIGURE 9.5 Serial activities are those that flow from one to the next, in sequence Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall

FIGURE Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall When the nature of the work allows for more than one activity to be accomplished at the same time, these activities are called concurrent and parallel project paths are constructed through the network.

FIGURE Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall

FIGURE 9.8 Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 09-16

FIGURE 9.10 Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 09-17

FIGURE Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall

o Past experience o Expert opinion o Mathematical derivation – Beta distribution o Most likely (m) o Most pessimistic (b) o Most optimistic (a) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 09-19

FIGURE 9.14 Symmetrical (Normal) Distribution for Activity Duration Estimation Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 09-20

FIGURE 9.15 Asymmetrical (Beta) Distribution for Activity Duration Estimation Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 09-21

09-22 Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall Table 9.2

o Forward pass – an additive move through the network from start to finish o Backward pass – a subtractive move through the network from finish to start o Critical path – the longest path from end to end which determines the shortest project length 09-23

Forward Pass Rules (ES & EF) o ES + Duration = EF o EF of predecessor = ES of successor o Largest preceding EF at a merge point becomes EF for successor Backward Pass Rules (LS & LF) o LF – Duration = LS o LS of successor = LF of predecessor o Smallest succeeding LS at a burst point becomes LF for predecessor 09-24

09-25 Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall Table 9.4 H Presentation E, F, G 2

FIGURE 9.16 Partial Project Activity Network with Task Durations Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 09-26

FIGURE 9.18 Activity Network with Forward Pass Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall

FIGURE 9.19 Activity Network with Backward Pass Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall

FIGURE 9.20 Project Network with Activity Slack and Critical Path Note: Critical path is indicated with bold arrows Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall

FIGURE Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall

Project ABC can be completed more efficiently if subtasks are used A(3)B(6)C(9) ABC=18 days Laddered ABC=12 days A 1 (1)A 2 (1)A 3 (1) B 1 (2)B 2 (2)B 3 (2) C 1 (3)C 2 (3)C 3 (3) 09-31

FIGURE Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall

o Eliminate tasks on the CP o Convert serial paths to parallel when possible o Overlap sequential tasks o Shorten the duration on critical path tasks o Shorten o early tasks o longest tasks o easiest tasks o tasks that cost the least to speed up 09-33

1. Understand and apply key scheduling terminology. 2. Apply the logic used to create activity networks, including predecessor and successor tasks. 3. Develop an activity network using Activity-on- Node (AON) techniques. 4. Perform activity duration estimation based on the use of probabilistic estimating techniques

5. Construct the critical path for a project schedule network using forward and backward passes. 6. Identify activity float and the manner in which it is determined. 7. Calculate the probability of a project finishing on time under PERT estimates. 8. Understand the steps that can be employed to reduce the critical path