University of Sunderland ENGM91 Unit 2 ENGM91 ACTIVITY PLANNING Unit 2 ENGM91 ACTIVITY PLANNING Unit 2

University of Sunderland ENGM91 Unit 2

ENGM91ENGM91

ACTIVITY PLANNING ACTIVITY PLANNING

Unit 2Unit 2


Introduction 1Introduction 1

• The unit will cover– Work breakdown structure (WBS)– Product breakdown Structure (PBS)– An introduction to system modelling– Precedence analysis– Gantt Charts– PERT / CPA

• On Arrow Networks• Precedence Networks

• Also …..– Microsoft Project will be covered in labs

• This is based on Gantt Charts and Precedence Networks


Introduction 2Introduction 2

– Activity Planning will help to:• ensure that the appropriate resources will be available

precisely when required• avoid different activities competing for the same

resource at the same time• produce a detailed schedule showing which staff carry

out each activity• Produce a detailed plan against which actual

achievement may be measured• produce a timed forecast• re-plan the project during its life to correct drift from a

target


Work Breakdown Work Breakdown Structure (WBS)Structure (WBS)

• WBS is the decomposition of work into progressively smaller and smaller chunks of work.

• The logical conclusion is when work cannot be usefully broken down any further for the tasks being undertaken


Work Breakdown Work Breakdown StructureStructure

Project

ProduceReport

ConductInvestigation



• Top LevelProject

• Level 1 Conduct Investigation



ConductInvestigation

Investigate hardware

Conductinterviews

Investigateother systems

Analyserequirements





• Level 2 Conduct Interviews



Conductinterviews

Sales manager

Managingdirector

Financedirector

Storesmanager






• Level 3 Interview Managing Director



InterviewMD

Review data flow diagrams

Conductinterview

Write andreview notes

Create dataflow diagrams






• Level 3 Interview Managing Director

• Level 4 Conduct Interview


Product Breakdown Product Breakdown Structure (PBS)Structure (PBS)

• Similar to WBS

• PBS is the break down of a product into it’s discrete components.

• a PBS can be included as part of a WBS


Product Breakdown Product Breakdown Structure (PBS)Structure (PBS)

• An example pbs – taken from a US MIL handbook

AircraftAircraft

Fire ControlFire ControlPropulsionPropulsionAirframeAirframe

SYSTEM

TECHNOLOGY DEVELOPMENT

WeaponWeapon

SUBSYSTEM

DetectDetect AimAim FireFire TrackTrack

AircraftAircraft

Fire ControlFire ControlPropulsionPropulsionAirframeAirframe

SYSTEM

TECHNOLOGY DEVELOPMENT

WeaponWeapon

SUBSYSTEM

DetectDetect AimAim FireFire TrackTrack


System ModellingSystem Modelling

Do I feellike getting

up?

Alarm goes off

Get up and goto bathroom

Press snoozebutton

Flowchart Of Getting Up In The Morning

fig. 1

No

Yes


System ModellingSystem Modelling

• IDEF0


IDEF0IDEF0


WBS and PBSWBS and PBS

• WBS, PBS and system modelling will assist in an understanding of the project

• WBS and PBS must be done to allow Precedence analysis to take place

• WBS and PBS do not necessarily set the precedence of a project

• Precedence within a project should be based on what is best for the timely and economic completion of the project


Precedence analysisPrecedence analysis

• Must be done before an activity plan can be produced

• Reviews the activities that are to be carried out

• Decides what activities must be carried out before particular activity can start


Gantt ChartsGantt Charts

• Developed by Henry Gantt, around 1917

• Gantt charts are easy to use and produce

• They are very useful for use on less complex projects

• Commonly used due to there simplicity

• Gantt charts are easily understood and easy to read



WEEK 1 WEEK 2 WEEK 3 WEEK 4 WEEK 5 WEEK 6Task 1Task 2Task 3Task 4Task 5Task 6



• Draw the following Gantt chart

Tasks Precedence Time

a - 5 days

b - 4 days

c a 6 days

d b 2 days

e b 5 days

f c,d 8 days



WEEK 1 WEEK 2 WEEK 3 WEEK 4Task aTask bTask cTask dTask eTask f


Network planning Network planning modelsmodels

• PERT• The Program Evaluation and Review Technique

• Developed by:– US Navy with– BOOZ-Allen Hamilton and– Lockheed Corporation for the– Polaris missile/submarine project in 1958



• CPM• Critical Path Method

– Also know as CPA• Critical Path Analysis

• Developed by– DuPont Inc in the– Late fifties early sixties to facilitate– building of complex process plant



• PERT– developed for use on R&D projects

• CPM– developed for use in construction projects

• When developed the two techniques were very similar

• Now there is virtually no difference between the two



• A simple on arrow network model

1

2

3

4

5

5

5

Start End

a

b

c

d

e

f

g

h


TerminologyTerminology

• Activity– A specific task, uses resources takes time to

complete

• Event– The result of completing an activity– Events use no resources– They are instances in time, points on the

network, conditions of a system that can be recognised



• Network– The combination or all activities (often drawn as

lines) and events (often drawn as nodes at the beginning and end of each line) defines the project and the activity precedence relationship.

– Arrow heads placed on the lines indicate the direction of flow. Before and an event can be realised all the activities that immediately precede it must be completed



• Path– The series of connected activities (or

intermediate events) between any two events in a network

• Critical– Activities, events, or paths, which, if delayed, will

delay the completion of the project– A project’s critical path is understood to mean

that sequence of critical activities (and critical events) that connect the project’s start event to its finish event



• On Arrow Network diagram showing critical path in red

1

2

3 4

5

6

A=6

B=4 D=4

C=3

E=3

F=10

H=2

G=3


Network syntaxNetwork syntax

• Time moves from left to right

• Nodes are numbered sequentially

• A network may not contain loops

• A network may not contain dangles

• Precedents are the immediate preceding activities

• Dummy activities can be used to indicate a particular precedence



• Time moves from left to right

• Nodes are numbered sequentially

1 2 3a b



• A network may not contain loops

1 2 3

4

This is not allowed

ab

cd



• A network may not contain dangles

1 2 3

4This is not allowed

a b

c



• Precedents are the immediate preceding activities

1 2 3Design Build

4Commission



• Dummy activities can be used to indicate a particular precedence

1 2 3 Wrong

1

2

43

Right

a

b

c

a

b c


On Arrow NetworksOn Arrow Networks

• Draw the following as an on arrow network

Tasks Precedence Time

a - 5 days

b - 4 days

c a 6 days

d b 2 days

e b 5 days

f c,d 8 days



• How to start …..

1

2

3

start

a

b



• What not to do

1

2

3

start

a

b

4

5

6

c

d

e



• A better way ……

1

2

3

start

a

b

c

d

e



• It is then less confusing that c & d go to the same event … but what about e & f ?

1

2

3

start

a

b

4

5

6c

d

e

f



• The completed on arrow network ….

1

2

3

start

a

b

4

5

c

de

f

end



• Another on arrow network to drawTasks Precedence Timea - 6 weeksb - 4 weeksc a 3 weeksd b 4 weekse b 3 weeksf - 10 weeksg e,f 3 weeksh c,d 2 weeks



• The network with activity times added

1 3 4 6

2

5

A=6C=3

B=4 D=4

F=10

E=3

G=3

H=2



• Each event circle can contain the information below

Eventnumber

Earliestdate

Latestdate

SlackEvent


Event numbersEvent numbers

1

2

3 4

5

6


Timed activitiesTimed activities

1

2

3 4

5

6

A=6

B=4 D=4

C=3

E=3

F=10

H=2

G=3


Forward passForward pass

1

2

3 4

5

6

A=6

B=4 D=4

C=3

E=3

F=10

H=2

G=3

0

6

4 9

10

13


Backward passBackward pass

1

2

3 4

5

6

A=6

B=4 D=4

C=3

E=3

F=10

H=2

G=3

0

6

4 9

10

13 1311

10

8

70


Event, Slack and Event, Slack and Activity FloatActivity Float

1

2

3 4

5

6

A=6

B=4 D=4

C=3

E=3

F=10

H=2

G=3

0

6

4 9

10

13 1311

10

8

700

2

3 2

0

0


The Complete On Arrow The Complete On Arrow NetworkNetwork

1

2

3 4

5

6

A=6

B=4 D=4

C=3

E=3

F=10

H=2

G=3

0

6

4 9

10

13 1311

10

8

700

2

3 2

0

0


Precedence NetworksPrecedence Networks

• Precedence network also known as Activity on Node

• Becoming more common as it is used by many project planning software packages

• Often preferred by project managers



• Syntax the same as for On Arrow networks– Except there are no dummy activities

• Precedence networks must start with a start node and end with a end node



• A simple precedence network

Start End

a

b

d

c

e

f

g

h


• This is the same network drawn as an On Arrow network

1

2

3

4

5

5

5

Start End

a

b

c

d

e

f

g

h



• A simple precedence network

Start End

a

b

d

c

e

f

g

h



• Draw the following as an Precedence network

Tasks Precedence Timea - 5 daysb - 4 daysc a 6 daysd b 2 dayse b 5 daysf c,d 8 days



• The completed Precedence Network

Start End

a

b

d

c

e

f


• The same network drawn as an On Arrow Network

1

2

3

start

a

b

4

5

c

de

f

end




Start End

a

b

d

c

e

f



• Another on precedence network to drawTasks Precedence Timea - 6 weeksb - 4 weeksc a 3 weeksd b 4 weekse b 3 weeksf - 10 weeksg e,f 3 weeksh c,d 2 weeks




Start End

a

b

d

c

e

f

h

g


• This is the same network drawn as an On Arrow network

1 3 4 6

2

5

A=6C=3

B=4 D=4

F=10

E=3

G=3

H=2




Start End

a

b

d

c

e

f

h

g



• Adding more information to the node

ES D EF

LS F LF

Earlieststart

Duration EarliestFinish

LatestStart

LatestFinish

Float

Description



• ES = latest (largest) EF of preceding activity– e.g. event may start at day zero - this actually

means the end of day zero or the beginning of day one !!!

• EF = activity ES + activity duration• LS = activity LF – activity duration• LF = earliest (smallest) LS of subsequent

activities.• Float = LS – ES or LF – EF


2 6 8

4 2 10

Description

3 2 5

8 5 10

Description

8 4 12

10 2 14

Description


8 4 12

10 2 14

Description

12 4 16

16 4 20

Description

12 6 18

14 2 20

Description



• Redraw the following with complete information in each node box

Tasks Precedence Timea - 5 daysb - 4 daysc a 6 daysd b 2 dayse b 5 daysf c,d 8 days



• Redraw the following with complete information in each node box

Tasks Precedence Timea - 6 weeksb - 4 weeksc a 3 weeksd b 4 weekse b 3 weeksf - 10 weeksg e,f 3 weeksh c,d 2 weeks


ConclusionConclusion

• Activity Planning

– Precedence analysis

– On Arrow networks

– Precedence networks


Exercise 1Exercise 1

Tasks Precedence Timea - 6 weeksb - 4 weeksc - 3 weeksd a 4 weekse b 3 weeksf b 2 weeksg c 3 weeksh d,e 2 weeksi f 1 weekj g,i 2 weeks



• Tasks Precedence Time• a - 3 weeks• b - 5 weeks• c a 7 weeks• d b 5 weeks• e c, d 6 weeks• f b 4 weeks• g b 8 weeks• h c, d 4 weeks• i e, f 3 weeks


Exercise 3Exercise 3• Tasks Precedence Time• a - 2 weeks• b - 4 weeks• c - 3 weeks• d a 3 weeks• e a 5 weeks• f c 6 weeks• g c 4 weeks• h d 4 weeks• i d 8 week• j b, e, f, i 2 weeks• k - 4 weeks• l g, k 3 weeks



• Tasks Precedence Time• a - 3 weeks• b a 5 weeks• c a 3 weeks• d c 1 weeks• e b 3 weeks• f b, d 4 weeks• g c 2 weeks• h g, f 3 weeks• i e, h 1 weeks



• Tasks Precedence Time• a - 3 weeks• b - 5 weeks• c a 14 weeks• d a 5 weeks• e b 4 weeks• f b 7 weeks• g d, e 8 weeks• h g, f 5 weeks

Documents

University of Sunderland ENGM91 Unit 2 ENGM91 ACTIVITY PLANNING Unit 2 ENGM91 ACTIVITY PLANNING Unit 2