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PROJECT MANAGEMENT
Building construction
© 1995 Corel Corp.
An Example
Project OrganizationWorks Best When
Work can be defined with a specific goal and deadlineThe job is unique or somewhat unfamiliar to the existing organizationThe work contains complex interrelated tasks requiring specialized skillsThe project is temporary but critical to the organization
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Project Planning, Scheduling,and Controlling
Project Planning1. Setting goals2. Defining the project3. Tying needs into timed project
activities4. Organizing the team
Project Scheduling1. Tying resources to specific
activities2. Relating activities to each other3. Updating and revising on a
regular basis
Time/cost estimatesBudgetsEngineering diagramsCash flow chartsMaterial availability details
CPM/PERTGantt chartsMilestone chartsCash flow schedules
Project Controlling1. Monitoring resources, costs, quality,
and budgets2. Revising and changing plans3. Shifting resources to meet demands
Reports• budgets• delayed activities• slack activities
Before Project During Project
Establishing objectivesDefining projectCreating work breakdown structure Determining resourcesForming organization
© 1995 Corel Corp.
Project Planning
Work Breakdown Structure
1. Project2. Major tasks in the project3. Subtasks in the major tasks4. Activities (or work packages) to
be completed
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Identifying precedence relationships Sequencing activitiesDetermining activity times & costsEstimating material & worker requirementsDetermining critical activities
© 1995 Corel Corp.
JF
M AM J J
MonthActivity
Design
Build
Test
PERT
Project Scheduling
Gantt chartCritical Path Method (CPM)Program Evaluation & Review Technique (PERT)
© 1984-1994 T/Maker Co.
Project Management Techniques
J F M A M J JTime Period
Activity
Design
Build
Test
Gantt Chart
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Service Activities for A Delta Jet During a 60 Minute Layover
Network techniquesDeveloped in 1950’s
CPM by DuPont for chemical plants (1957)PERT by Booz, Allen & Hamilton with the U.S. Navy, for Polaris missile (1958)
Consider precedence relationships and interdependenciesEach uses a different estimate of activity times
PERT and CPM
Milwaukee General Hospital’s Activities and Predecessors
F, GInspect and testH
D, EInstall air pollution deviceG
CInstall pollution control systemF
CBuild high-temperature burnerE
A, BPour concrete and install frameD
AConstruct collection stackC
-Modify roof and floorB
-Build internal componentsA
Immediate Predecessors
DescriptionActivity
5
Start
A
B
C
D
E
F
G
H
F, GInspect and testHD, EInstall air pollution deviceG
CInstall pollution control systemFCBuild high-temperature burnerE
A, BPour concrete and install frameDAConstruct collection stackC-Modify roof and floorB-Build internal componentsA
Immediate Predecessors
DescriptionActivity
Latest Start and Finish Steps
Latest Finish
ES
LS
EF
LF
Earliest Finish
Latest Start
Earliest Start
Activity Name
Activity Duration
Provides activity informationEarliest (ES) & latest (LS) startEarliest (EF) & latest (LF) finishSlack (S): Allowable delay
Identifies critical pathLongest path in networkShortest time project can be completedAny delay on critical path activities delays projectCritical path activities have 0 slack
Critical Path Analysis
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Begin at starting event and work forwardES = 0 for starting activities
ES is earliest startEF = ES + Activity time
EF is earliest finishES = Maximum EF of all predecessors for non-starting activities
Earliest Start and Finish Steps
Begin at ending event and work backwardLF = Maximum EF for ending activities
LF is latest finish; EF is earliest finishLS = LF - Activity time
LS is latest startLF = Minimum LS of all successors for non-ending activities
Latest Start and Finish Steps
Latest Start and Finish Steps
Latest Finish
ES
LS
EF
LF
Earliest Finish
Latest Start
Earliest Start
Activity Name
Activity Duration
7
A C
FH
C4
10 3
713
HB
28 2
410
HA
06 2
28
Earliest Start
We have 13 days for this project
We can begin the project as early as day 0 ---immediately
Earliest Finish
Task A costs 2 days, so the earliest day we can finish it is day 2
Latest Finish
We must finish the project in day 13, so the latest finish day for task C is day 13
Latest Start
Task C takes 3 days, so the latest time that we should begin it is day 10
Critical Path forMilwaukee General Hospital
Start
A
B
C
D
F
F
G
H
Arrows show
precedence
relationships
Slack=0
Start
A
B
C
D
F
F
G
HH
1313 2
1515
HG
88 5
1313
HF
410 3
713
HC
22 2
44
HE
44 4
88
HD
34 4
78
HB
01 3
34
HA
00 2
22
H00 0
00
Slack=0 Slack=0
Slack=0
Slack=0
Slack=6
Slack=1Slack=1
Start
Earliest Start
Earliest Finish
Latest Finish
Latest Start
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Gantt ChartEarliest Start and Finish
Milwaukee General HospitalMilwaukee General Hospital
A Build internal componentsB Modify roof and floorC Construct collection stackD Pour concrete and install frameE Build high-temperature burnerF Install pollution control systemG Install air pollution deviceH Inspect and test
1 2 3 4 5 6 7 8 9 10 1112 13 1415 16
Gantt ChartLatest Start and Finish
Milwaukee General HospitalMilwaukee General Hospital
A Build internal componentsB Modify roof and floorC Construct collection stackD Pour concrete and install frameE Build high-temperature burnerF Install pollution control systemG Install air pollution deviceH Inspect and test
1 2 3 4 5 6 7 8 9 10 1112 13 1415 16
3 time estimatesOptimistic times (a)Most-likely time (m)Pessimistic time (b)
Follow beta distributionExpected time: t = (a + 4m + b)/6Variance of times: v = (b - a)2/6
PERT Activity Times
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Expected project time (T)Sum of critical path activity times, t
Project variance (V)Sum of critical path activity variances, v
Used to obtain probability of project completion!
Project Times
© 1995 Corel Corp.
PERT Probability Example
You’re a project planner for General Dynamics. A submarine project has an expected completion time of 40 weeks, with a standard deviation of 5 weeks. What is the probability of finishing the sub in 50 weeks or less?
T = 40
s = 5
50 X
Normal Normal DistributionDistribution
Z X T= - = - =s
50 405
2 0.
mz = 0
s Z = 1
Z2.0
Standardized Normal Standardized Normal DistributionDistribution
Converting to Standardized Variable
Due date Expected date of finish
Standard deviation
10
mz = 0
s Z = 1
Z2.0
Z .00 .01
0.0 .50000 .50399
: : : :
2.0 .97725 .97784 .97831
2.1 .98214 .98257 .98300
Standardized Normal Probability Standardized Normal Probability Table (Portion)Table (Portion)
Probabilities in bodyProbabilities in body
Obtaining the Probability
.02
.50798
.97725
Variability of Completion Time for NoncriticalPaths
Variability of times for activities on noncritical paths must be considered when finding the probability of finishing in a specified time.Variation in noncritical activity may cause change in critical path.
Steps in Project Crashing
Compute the crash cost per time period. For crash costs assumed linear over time:
Using current activity times, find the critical pathIf there is only one critical path, then select the activity on this critical path that (a) can still be crashed, and (b) has the smallest crash cost per period. Note that a single activity maybe common to more than one critical pathUpdate all activity times.
)Crash time time(Normalcost Normalcost(Crash periodper cost Crash
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