Project Management Tools
Stephanie Schmit
June 24, 2013
Source: Project Engineering ESD.062 / Oliver de Weck
ESD.052 Project Engineering Page 2
Methods and Tools you will learn
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Work breakdown structure
Task List
Scheduling and Gantt Charts: Critical Path Method
Tasks are the building blocks of projects
Project = set of related tasks
3
Work Breakdown Structure (WBS)
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Used to create the task (job) list
Tree-decomposition of project tasks
WBS identifies “terminal elements”
The key starting point for project planning
Required by contracts as part of the SOW
Can be activity-oriented or deliverable- oriented
Use “sticky-notes” method early on
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Carl L. Pritchard. Nuts and Bolts Series 1: How to Build
a Work Breakdown Structure. ISBN 1890367125
Job A
Job B
Job X
Job G
4
Example Work Breakdown Structure
HumLog DC Project
1 Planning
1.1
Location
Analysis
1.2
Capacity
Modeling
1.3
Transportation
Analysis
2 Contracting
2.1
Government
Approval
2.2
Request for
Proposal
2.3
Evaluate
Proposals
2.4
Select Main
Contractor
2.5
Finalize Contract
3 Staffing
4 Construction
3.1
Staffing for
Operations
3.2
Staff Training
And Instruction
4.1
Site Preparation
4.2
Dig and Pour
Foundation
4.3
Erect Main
Structure
4.4
Install Building
Systems
4.5
Install Security
Systems
5 Commissioning
5.1
Stock Up
Initial Inventory
5.2
Commissioning
And Test
5.3
Final Acceptance
IOC
5
Discussion Point
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Why is it difficult to come up with a
good WBS (task list, task structure) in a
complex project?
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Not all tasks known ahead of time if
completely new product/system
Others…?
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WBS Guidelines
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No more than 100-200 terminal elements, if
more  use subprojects
Can be up to 3-4 Levels deep
Not more than 5-9 jobs at one level
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Human cognitive “bandwidth” only 3 bits=23=8
Short term memory for most people 5-9 items
Poorer planning if “too-fine grained” – dilution of
attention
The more tasks there are, the more intricate
dependencies there will be to keep track of
Jobs should be of similar size/complexity
Manageable chunks  sense of progress
Level of graininess  very difficult to answer
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Task List
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List all tasks in a table with
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Identifying symbol (tag, ID number)
Task description
Immediate prerequisite jobs (predecessors)
Expected task duration
Arrange jobs in “technological order”
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No job appears in the list until all its predecessors
have been listed
Iterations are NOT allowed  “cycle error”
Job a precedes b precedes c precedes a
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Task List – HumLog DC Project
ID
WBS
1
Task Description
Predecessor
Start – Project Kickoff
Duration (wks)
0
2
1.1
Location Decision
1
4
3
1.2
Capacity Modeling
2
2
4
1.3
Transportation Analysis
2
2
5
2.1
Obtain Government Approval
3
8
6
2.2
Request for Proposal
4,5
4
7
2.3
Evaluate Proposals
6
2
8
2.4
Select Main Contractor
7
1
9
2.5
Finalize Main Construction Contract/Negotiations
8
2
10
4.1
Site Preparation
9
2
11
4.2
Dig and Pour Foundation
10
3
12
4.3
Erect Main Structure
11
4
13
3.1
Staffing for Operations
9
6
14
4.4
Install Building Systems (Electrical)
12
2
15
4.5
Install Safety and Security Systems
14
2
16
4.6
Install Inventory Management System (RFID)
14
2
17
4.7
Install Communications System
14
1
18
5.1
Stock Up on Initial Inventory
15, 16
3
19
3.2
Staff Training and Instruction
13
1
20
5.2
Commissioning and Test
19, 18, 17
4
21
5.3
Final Acceptance and IOC
20
1
End – Project Finish
21
0
22
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Gantt Charts
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Attributed to Henry Gantt – most popular PM tool (80%)
Used to plan big shipbuilding projects (cargo ships WWI)
Graphical way of showing task durations, project schedule
Does not explicitly show relationships between tasks
Limited use for project tracking
Easy to understand
calendar
today
completion
Gantt Chart Builder System (Excel) 1.6
08 Sep'03
Bus Unit
Mkt
Sys
Eng
Sys
Mfg
Sys
Project
Project "XYZ"
Customer Clinic
Requirements Definition
Parts Design
Design Review
Manufacturing
Product Release
tasks
%
30
100
100
50
0
0
0
Start
9-Sep-03
09-Sep-2003
11-Sep-2003
15-Sep-2003
23-Sep-2003
24-Sep-2003
06-Oct-2003
Finish
6-Oct-03
12-Sep-2003
15-Sep-2003
22-Sep-2003
23-Sep-2003
05-Oct-2003
06-Oct-2003
08/09
actual
15/09
22 Sep'03
22/09
29/09
06 Oct'03
06/10
13/10
milestone
D
planned
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CPM Assumptions
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Project consists of a collection of well defined
tasks (jobs)
Project ends when all jobs completed
Jobs may be started and stopped
independently of each other within a given
sequence (no “continuous-flow” processes)
Jobs are ordered  “technological sequence”
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Critical Path
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CP is the “bottleneck route”
Shortening or lengthening tasks on the critical path
directly affects project finish
Duration of “non-critical” tasks is irrelevant
“Crashing” all jobs is ineffective, focus on the few % of
jobs that are on the CP
“Crashing” tasks can shift the CP to a different task
Shortening tasks – technical and economical challenge
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How can it be done?
Previously non-critical tasks can become critical
Lengthening of non-critical tasks can also shift the
critical path
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Discussion Point
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What is the usefulness of knowing the
Critical Path in a project?
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Tells which task to shorten to finish project
earlier.
Others …?
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Latest Start and Finish Times
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Set target finish time for project: T >= F
Usually target is a specific calendar date,
e.g. October 1, 2010
When is the latest date the project can be
started?
Late Finish (LF) - latest time a job can be
finished, without delaying the project
beyond its target time (T)
Late Start: LS = LF-t
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Slack
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Some tasks have ES=LS --> no slack
Total Slack of a task TS=LS-ES
Maximum amount of time a task may be delayed
beyond its early start without delaying project
completion
Slack time is precious … managerial freedom, don’t
squander it unnecessarily
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e.g. resource, work load smoothing
When T=F then all critical tasks have TS=0
At least one path from Start->Finish with critical jobs
only
When T>F, then all critical jobs have TS=T-F
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Example Gantt Chart
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Goal: Complete big project by deadline!
Build part A
(3 days)
Deadline
15 days away
Assemble part AB
(5 days)
Build part B
(2 days)
Finish
(2 days)
Build part C
(6 days)
now
time
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Example Gantt Chart
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Goal: Complete big project by deadline!
Build part A
(3 days)
Build part B
(2 days)
Finish
(2 days)
Build part C
(6 days)
now
Deadline
15 days away
Assemble part AB
(5 days)
Critical Path = 10
Float time = 5
time
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Example Gantt Chart
Finished
Critical Path
7 days later…
Build part A
(3 days)
Assemble part AB
(5 days)
Build part B
(2 days)
Finish
(2 days)
Build part C
(6 days)
now
Deadline
Now 8 days away
Critical Path = 8
days
Float time = 0 days
time
No more float time!
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Main CPM Errors that people make
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Estimated job times are wrong
Predecessor relationships may contain cycles  “cycle
error”
List of prerequisites contains more than the immediate
predecessors, e.g. 12, 23 and 1,23
Overlooked some predecessor relationships
Some predecessor relationships may be listed that are
spurious
and …. Some tasks/jobs may be missing !!!
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Summary
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Work breakdown structure
Task List
Scheduling and Gantt Charts: Critical Path
Method
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