OM480 Defining the Project Parameters – Scheduling 101 (With Material from the Text Authors)

OM480

Defining the Project Parameters – Scheduling

101(With Material from the Text Authors)

Overview

• Scheduling

• Precedence Relationships

• PERT/CPM

• Critical Chain

• Activity Networks

Scheduling

• Project = Problem scheduled for solution• Requires:

– Planning– Organizing– Coordinating– Directing– Controlling

• gninnalP drawkcaB• Forward Execution

Project Management Trade-Offs

Performance

Quality

Cost Time

©

Project Priority Matrix

Constrain

Enhance

Accept

Time Performance Cost

WBS/Work Packages to Network

Circuitboard

Designcost

account

Productioncost

account

Testcost

account

Softwarecost

account

Lowestelement

Organizatio

Units

DesignWP D-1-1 SpecificationsWP D-1-2 Documentation

ProductionWP P-10-1 Proto 1WP P-10-2 Final Proto 2

Test systemsWP T-13-1 Test

SoftwareWP S-22-1 Software preliminaryWP S-22-1 Software final version

BProto 1

5

DFinal

proto 24

ASpecifications

and documentation2

CPreliminary

software3

FFinal

software2

KTest

3

AD-1-1D-1-2

BP-10-1

DP-10-2

FS-22-2

KT-13-1

CS-22-1

Duration and Activities

• Effort is not duration– Time spent in actual “work”

• Duration lasts longer– Elapsed time from activity start to finish

– Imagine “NFL two-minute warning”

• See Page 183-184 for techniques• Realities of Duration Planning

– Deliveries

– Breakdowns/Repairs

– Approvals

PERT

• PERT– Program Evaluation and Review Technique– US Navy “Polaris Missile” Program – 1950s– Statistical manipulation of 3 duration estimates

• Most Optimistic• Most Likely• Most Pessimistic

– Probability-based• P(MO) + P(ML) + P(MP) = Duration

– More reflective of “realities”

CPM

• CPM– Critical Path Method– DuPont and Remington Engineers – 1950s

• New Product/Process Roll-out

– Less sophisticated than PERT– Relies on one duration estimate– Same duration techniques as PERT

Hypothetical Network

2 5 61

4

3

Activity and Project FrequencyDistributions

ACTIVITY PROJECT

a m b TE

(A) (B)

PERT Activity Calculation

T(e) = a + 4m + b a = Most Optimistic (MO)

6 m = Most Likely (ML)

b = Most Pessimistic (MP)

T(e) = Activity Duration

When Probabilities are “Unknown” or too lazy/scared

To calculate!!!

Possible Project Durations

TE=64

TS=67

PERT Schedule Probability

Z is derived from a table of predetermined probabilities

Z = T(S) – T(E) Z = Probability of SD(T[E])2 Meeting Schedule

T(S) = Scheduled Duration

T(E) = Critical Path Duration

PERT SimulationActivity Times and Variances

Activity a m b t(e)

1-2 17 29 47

2-3 6 12 24

2-4 16 19 28

3-5 13 16 19

4-5 2 5 14

5-6 2 5 8

Activity a m b t(e) [(b-a)/6]2

Var

1-2 17 29 47

2-3 6 12 24

2-4 16 19 28

3-5 13 16 19

4-5 2 5 14

5-6 2 5 8

Hypothetical Network

2 5 61

4

3

5

16

620

13

30

TE=62

Calculate t(e) and Z for this network……

Z Table

Z Value Probability Z Value Probability

-2.0 0.02 +2.0 0.98

-1.5 0.07 +1.5 0.93

-1.0 0.16 +1.0 0.84

-0.7 0.24 +0.7 0.76

-0.5 0.31 +0.5 0.69

-0.3 0.38 +0.3 0.62

-0.1 0.36 +0.1 0.54

Activity Networks

• Flowchart-based representation of activities– Sequenced – Precedence

• Consecutiveness• Concurrency

• Activity on Node– Action is in the “box”

• Activity on Arrow– Activity is on the “line”

Critical Chain

• Based on “Theory of Constraints”– Eliyahu Goldratt “The Goal”

Rollup of Network Plans

WP-2

A

B

C

D

E

F

WP-1

WP-4

WP-3

Level 1 - Milestone Plan

Level 2 - Plans

Level 3 - Plans

Air Control Inc., Custom OrderProject—Gantt Chart

0 7 14 21 28 35 42 49

2

13

15

10

18

15

10

5

Order review

Design custom parts

Order standard parts

Produce standard parts

Software development

Manufacture customhardware

Assemble

Test

Software Conversion ProjectResponsibility Matrix

Engineeringdepartment

R A C

Kim C C

Ron C R A A A

Holly R

James R

Chuck A A

Wendy A R

Documentsdepartment

R R C

Sys

tem

spec

ific

atio

ns

Cod

ing

Use

rm

anua

l

For

ms

Cro

ssov

erpl

an

Tra

in s

taff

Tes

tActivities

Org

aniz

atio

nU

nit/

Indi

vidu

al Legend

R = ResponsibilityC = ContributesA = Advises

Air Control Inc., Custom OrderProject—Network Diagram

1 Orderreview

20 20 2

2

3

4

5

Softwaredevelopment

Orderstandard

parts

Producestandard

parts

Designcustom parts

18 2 2022 40

15 2 1715 30

10 2 12 5 15

13 2 12 5 15

6

7 8

Manufacturecustom

hardware

Assemble Test

Activity8#

Legend

1515 3015 30

1030 4030 40

540 4540 45

DurationES EFLS LF

©

Air Control Inc., Custom OrderProject—Network with Dates

1 Orderreview

2 1-Jan 2-Jan 1-Jan 2-Jan

2

3

4

5

Softwaredevelopment

Order standard parts

Produce standard parts

Designcustom parts

18 2-Jan 20-Jan22-Jan 9-Jan




6

7 8

Manufacturecustom

hardware

Assemble Test

Activity8#

Legend




DurationES date EF dateLS date LF date

AOA Network Building Blocks

8079Install software

EventActivity

Partial Koll Business CenterAOA Network

4

5

1 32AApplication

approval

DService

availabilitycheck

CTrafficstudy

BConstruction

plans

Partial AOA Network Koll Network

2

3

1 4A

X

C

B

E

(A)

2

3

1 4A

B

C

X

E

(B)

2 31

4

A

B

XC

E

(C)

Partial AOA Network Koll Network

2 31

4

A

B

CX

E

(D) 5D

2 31

4

A

B

CX

E

(E)

5

D

F?

Activity-on-Arrow Network

KOLL BUSINESS CENTERCounty Engineers Design Department

2 31

4

A5

B

C10

X

5

150

6 7 8

0Y

F10

G170

H35

E15

D5

ActivityDuration

Legend

Activity-on-Arrow NetworkForward Pass


2 31

4

A5

B

C10

X

5

150

6 7 8

0Y

F10

G170

H35

E15

D5Legend

5

20

0 15 20 30 200 235 235

5 15

1520

20

10

30 200

35

235

E(=ES)

L(=LF)

SlackEF

Activity-on-Arrow NetworkBackward Pass


2 31

4

A5

B

C10

X

5

15 0

6 7 8

0Y

F10

G170

H35

E15

D5Legend

5

20

0 20 20 30 200 235 235

5

15

20

20

30 200 235

E(=ES)

L(=LF)

SlackLS EF

0 10

185

20

Activity-on-Arrow Network Backward Pass, Forward Pass, and Slack


2 31

4

A5

B

C10

X

5

150

6 7 8

0Y

F10

G170

H35

E15

D5Legend

5 5

0

20 20

0

0 0

0

15 20

5

20 20

0

30 30

0

200 200

0

235 235

0

5

15

20

20

30 200 235

E(=ES)

L(=LF)

SlackLS EF

0 10

185

205

20

15

20

10

30 200

35

Air Control Inc., Custom Order Project—AOA Network Diagram

2

3

14

Orderreview

20 20 2

5 6 7

Software development18

0 2022 40

Order standard parts15

2 1715 30

Produce standard parts10

2 1215 15

Design custom parts

132 152 15

Manufacture Custom Hardware

1515 3015 30

Assemble10

30 4030 40

Test5

40 4540 45

LegendDur.

ES EFLS LF

Activity-on-Node Network Fundamentals

X

Y

Z

Y and Z are preceded by X

Y and Z can begin at thesame time, if you wish

(B)

A B C

A is preceded by nothingB is preceded by AC is preceded by B

(A)

J

K

L

M

J, K, & L can all begin atthe same time, if you wish(they need not occursimultaneously)

All (J, K, L) must becompleted before M canbegin

but

X Z

AAY

(C)

(D)

Z is preceded by X and Y

AA is preceded by X and Y

Activity-on-Node Network Fundamentals


B

15

Constructionplans

C

10

Trafficstudy

D

5

Servicecheck

A

5

Applicationapproval

ES ID EF

SL

LS Dur LF

Description

F

10

Commissionapproval

G

170

Wait for construction

H

35

Occupancy

E

15

Staff report

EF

Activity-on-Node Network Forward Pass

5 B 20

15

Constructionplans

C

10 10 20

Trafficstudy

D

15 5 20

Servicecheck

A

0 5 5

Applicationapproval

ES ID EF

SL

LS Dur LF

Description

F

20 10 30

Commissionapproval

G

30 170 200


H

200 35 235

Occupancy

20 E 35

15

Staff report

EF


20

15

20

15

10

200

35

Activity-on-Node Network Backward Pass

B

5 15 20

Constructionplans

C

10 10 20

Trafficstudy

D

15 5 20

Servicecheck

A

0 5 5

Applicationapproval

ES ID EF

SL

LS Dur LF

Description

F

20 10 30

Commissionapproval

G

30 170 200


H

200 35 235

Occupancy

E

185 15 200

Staff report

LS


20

20

185

185

10

15

5

20

Activity-on-Node Network with Slack

5 B 20

0

5 15 20

Constructionplans

5 C 15

5

10 10 20

Trafficstudy

5 D 10

10

15 5 20

Servicecheck

0 A 5

0

0 5 5

Applicationapproval

ES ID EF

SL

LS Dur LF

Description

20 F 30

0

20 10 30

Commissionapproval

30 G 200

0

30 170 200


200 H 235

0

200 35 235

Occupancy

20 E 35

165

185 15 200

Staff report

LS EF


20

15

185

185

10

15

5

20

20

20

10

20

15

Example of Laddering UsingFinish-to-Start Relationship

Trench1/3

Trench1/3

Trench1/3

Lay pipe1/3

Lay pipe1/3

Lay pipe1/3

Refill1/3

Refill1/3

Refill1/3

AON network

Finish-to-Start Relationship

X YLag 2

Start-to-Start Relationship

ActivityM

ActivityN

ActivityP

ActivityQ

Lag 5

A B

Use of Lags to Reduce Detail

Trench1 mile

Lay pipe1 mile

Lag 3

Refill1 mile

Lag 3

Finish-to-Finish Relationship

Lag 4Prototype

Testing

Start-to-Start Relationship

Lag 3

Systemdocumentation

Testing

Combination Relationships

Lag 2

Code

Debug

Lag 4

Network Using Lags

5 B 15

00

5 10 15

10 D 25

1111

21 15 36

0 A 5

0 0

0 5 5

ES ID EF

SL SL

LS Dur LF

15 E 30

05

30 10 45

30 F 40

05

30 10 45

40 H 50

5 0

45 5 50

15 C 20

5 5

20 5 25

Legend25 G 40

110

36 4 40

Lag 5

Lag 10

Lag 10

Lag 5Lag 10

Hammock Activity Example

5 B 6

0

5 1 6

11 E 21

0

11 10 21

0 A 5

0

0 5 5

ES ID EF

SL

LS Dur. LF

Description

6 D 10

8

14 4 18

10 F 13

8

18 3 21

21 F 25

0

21 4 25

6 C 11

0

6 5 11

Legend5 G 13

Hammock

8