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Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall Day 19.

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Presentation on theme: "Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall Day 19."— Presentation transcript:

1 Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall Day 19

2 Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall Ch 1 -2 Agenda Questions? IP Part 4 Missing.mmp file with costs update IP Part 5 Due Nov 18 Developing a Project Schedule Assignment 6 Corrected 3 As and 1 B Assignment 7 Posted Due Nov 18 Only one more Exam 2 Corrected 2 As, 1 B and 1 C Only one more Finish Critical Chain Project Scheduling

3 Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall Finals Rescheduling Do IP Project presentation on Dec 12 Exam 3 done asynchronously via Blackboard on Dec 16 Final IP Project Due Dec 18 3

4 Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall Project Scheduling: Lagging, Crashing, and Activity Networks 10-04

5 Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall Boeing st Delivery September 25, uestTimeout=500&optReportType=AnnOrd&pageid=m15521

6 Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall Chapter 10 Learning Objectives After completing this chapter, students will be able to: Apply lag relationships to project activities. Construct and comprehend Gantt charts. Recognize alternative means to accelerate projects, including their benefits and drawbacks. Understand the trade-offs required in the decision to crash project activities. Develop activity networks using Activity-on-Arrow techniques. Understand the differences in AON and AOA and recognize the advantages and disadvantages of each technique

7 Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall Lags in Precedence Relationships The logical relationship between the start and finish of one activity and the start and finish of another activity. Four logical relationships between tasks 1. Finish to Start 2. Finish to Finish 3. Start to Start 4. Start to Finish 10-07

8 Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall Finish to Start Lag Most common type of sequencing Shown on the line joining the modes Added during forward pass Subtracted during backward pass 0 A 6 Spec Design 6 6 B 11 Design Check 5 15 C 22 Blueprinting 7 Lag 4 This lag is not the same as activity slack 10-08

9 Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall Finish to Finish Lag Two activities share a similar completion point The mechanical inspection cannot happen until wiring, plumbing, and HVAC installation are complete 10 A 16 Plumbing 6 16 B 21 HVAC 5 21 C 22 Inspection 1 15 D 21 Wiring 6 Lag

10 Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall Start to Start Lag Logic must be maintained by both forward and backward pass 31 A 33 Plumbing 6 33 B 36 HVAC 5 36 C 37 Inspection 1 30 D 36 Wiring 6 Lag

11 Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall Start to Finish Lag Least common type of lag relationship Successors finish dependent on predecessors start 22 A 28 Plumbing 6 28 B 33 HVAC 5 33 C 34 Inspection 1 30 D 36 Wiring 6 Lag

12 Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall Gantt Charts Establish a time-phased network Can be used as a tracking tool Benefits of Gantt charts 1. Easy to create and comprehend 2. Identify the schedule baseline network 3. Allow for updating and control 4. Identify resource needs

13 Create a Gantt chart based on the activities listed in the table. TaskTimePredTaskTimePred Z8--U3W Y5ZT6V X8ZS7U,T W4Y,XR9S V5W gantt.mpp

14 Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall FIGURE 10.8 Completed Gantt Chart for Project Delta Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 10-14

15 Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall FIGURE 10.9 Gantt Chart for Project Delta with Critical Path Highlighted Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall

16 FIGURE Gantt Chart with Resources Specified Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall

17 FIGURE Gantt Chart with Lag Relationships Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall

18 Gantt Chart with Lag Relationships 18

19 Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall Crashing The process of accelerating a project Principal methods for crashing Improving existing resources productivity Changing work methods Compromise quality and/or reduce project scope Institute fast-tracking Work overtime Increasing the quantity of resources 10-19

20 Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall Managerial Considerations Determine activity fixed and variable costs The crash point is the fully expedited activity Optimize time-cost tradeoffs Shorten activities on the critical path Cease crashing when the target completion time is reached the crashing cost exceeds the penalty cost 10-20

21 CRASHING ACTIVITIES – AN EXAMPLE Formula Slope = crash cost – normal cost normal time – crash time Example – Calculating the Cost of Crashing SUPPOSE: NORMAL ACTIVITY DURATION = 8 WEEKS NORMAL COST = $14,000 CRASHED ACTIVITY DURATION = 5 WEEKS CRASHED COST = $23,000 THE ACTIVITY COST SLOPE = 23,000 – 14,000 or, $9,000 = $3,000 per week 8 – 5 3

22 Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall Project Activities and Costs Table 10.1 Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall

23 FIGURE Time–Cost Trade-Offs for Crashing Activities Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 10-23

24 Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall Project costs PreNormalCrashedCrash/dayDays Gained activityDurationCostDurationCost A BA CA DA EC,D FB GD HE,F,G Total

25 Project time = 28 days Project Cost = $22450 Normal Netw0rk

26 Project time = 19 days Project Cost = $37,500 Fully Crashed Netw0rk

27 Project time = 19 days Project Cost = $34,200 (save $3,300) Partially Crashed Netw0rk

28 FIGURE Relationship Between Cost and Days Saved in a Crashed Project Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall 10-28

29 Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall Other costs Previous examples only includes direct costs What about Indirect costs (overhead) $ per day overhead Late penalties $ per day late

30

31 What is the lowest cost to complete this project in 53 weeks? Times are in weeks and costs in dollars. ActivityPredNormal Time Min Time Normal Cost Crash Cost A BA CA DB, C ED FD GE, F HG crash.mppcrash.mpp, crash.xlscrash.xls

32 Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall Activity on Arrow Networks Activities represented by arrows Widely used in construction Event nodes easy to flag Forward and backward pass logic similar to AON Two activities may not begin and end at common nodes Dummy activities may be required

33 Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall FIGURE Notation for Activity-on-Arrow (AOA) Networks Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall

34 Project delta ActivityPreDuration A5 BA5 CA6 DB,C13 EB6 FD4 GC9 HE,F,G2

35 Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall FIGURE Sample Network Diagram Using AOA Approach Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall

36 FIGURE 10.20A Representing Activities with Two or More Immediate Successors(Wrong) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall

37 FIGURE 10.20B Alternative Way to Represent Activities with Two or More Immediate Successors (Wrong) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall

38 FIGURE 10.20C Representing Activities with Two or More Immediate Successors Using Dummy Activities (Better) Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall

39 FIGURE Partial Project Delta Network Using AOA Notation Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall

40 FIGURE Completed Project Delta AOA Network Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall

41 FIGURE Project Delta Forward Pass Using AOA Network Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall

42 FIGURE Project Delta Backward Pass Using AOA Network Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall

43 1. Use AOA to sketch the network that represents the project as described in the table. 2. Calculate early and late start and finish times for all activities. ActivityTimePredActivityTimePred A3--F4D B5AG2C C7AH5E,F,G D3B,C E5B

44 9-44

45 Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall Controversies in the Use of Networks Networks can be too complex Poor network construction creates problems Networks may be used inappropriately When employing subcontractors The master network must be available to them All sub-networks must use common methods Positive bias exists in PERT networks 10-45

46 Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall Summary 1. Apply lag relationships to project activities. 2. Construct and comprehend Gantt charts. 3. Recognize alternative means to accelerate projects, including their benefits and drawbacks. 4. Understand the trade-offs required in the decision to crash project activities. 5. Develop activity networks using Activity-on-Arrow techniques. 6. Understand the differences in AON and AOA and recognize the advantages and disadvantages of each technique

47 10-47 Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall


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