PROJECT TIMEMANAGEMENTPROJECT TIMEMANAGEMENT

IMPORTANCEIMPORTANCE

Average time overrun on unsuccessful IT projects was 222 % of the original estimation.

1995 CHAOS Report

It was reduced to 63% in 20002000 CHAOS Report

• One may massage the overrun of cost and scope• Time passes no matter what happens on a project• Time can be measured easily and simply

Conflict intensity over the life of a project

Conflict intensity over the life of a project

0.40

0.35

0.30

0.25

0.20

0.15

0.10

0.05

0.00

ProjectFormation

EarlyPhase

MiddlePhase

EndPhase

Schedule Priority Manpower Tech. option

Procedure cost Personality

Co

nfl

ict

Inte

nsi

ty

AverageTotal

Conflict

MAIN PROCESS OF PTMMAIN PROCESS OF PTM

• Activity definitioninvolves identifying the specific activities to produce the deliverables.

• Activity duration estimatinginvolves estimating the work periods that are needed to complete individual activities.

• Activity sequencinginvolves identifying and documenting the relationships between activities.

• Schedule developmentinvolves activity estimating, sequencing and resources

• Schedule controlinvolves controlling and managing changes to the project schedule

ACTIVITY (TIME) ESTIMATIONACTIVITY (TIME) ESTIMATION

Define project type and Understand scopeReusable software resourcesSkill set neededSoftware project estimation

Estimation of resource, schedule, and cost based on conditions defined by Program Plan and Engineering Plan.

Project Type:Product: requirements from marketCustomized: RFP and proposalSystem Integration: RFP and proposal

People

Reusable

Tools

Project Resources

ACTIVITY (TIME) ESTIMATIONACTIVITY (TIME) ESTIMATION

Problem-Based Estimation• Line-Of-Code-Based (LOC)• Function-Point-Based (FP)

Process-Based Estimation

History Record-Based

ESTIMATION FAILUREESTIMATION FAILUREEstimation of resource (human resource, reusable, skill set, domain expertise), schedule, and cost based on conditions defined by Program Plan and Engineering Plan.

FAILED PROJECT IRADIUMLow Orbit, 66 satellites, 11 ground stationsInternational: US, Russian, China, …Postmortem :

MarketingTime to marketTargeting (small customer group)Technology

Management (estimation)ScopeSize

Payload

Cross link

In orbit link

handset

Groundstations

WORK BREAKDOWNWORK BREAKDOWNWORK BREAKDOWN STRUCTURE (WBS)

Define product scopeIdentify function by decomposing scopeDo while functions remain

select a functionassign all functions to sub functions listdo while sub functions remain

select a functionif similar to historical functionthen use its estimation + changeelse

if the function can be estimatedthen estimateelse further decomposeend if

end ifend do

End do

EXAMPLES OF ESTIMATION

EXAMPLES OF ESTIMATION

The CAD software will accept two- and three-dimensional geometric data from an engineer. The engineer will interact and control the CAD system through a user interface that will exhibit characteristics of good human/machine interface design. All geometric data and other supporting information will be maintained in a CAD database. Design analysis modules will be developed to produce the required output, which will be displayed on a variety of graphics devices. The software will be designed to control and interact with peripheral devices that include a mouse, digitizer, laser printer and plotter.

• User interface and control facilities (UICF)• Two-dimensional geometric analysis (2DGA)• Three-dimensional geometric analysis (3DGA)• Database management (DBM)• Computer graphics display facilities (GCDF)• Peripheral control function (PFC)• Design analysis modules (DAM)

Computer-aided Design Application For Mechanical Component:

LOC-BASED ESTIMATIONLOC-BASED ESTIMATIONFUNCTION EST. LOC

User interface and control facilities (UICF)

Two-dimensional geometric analysis (2DGA)

Three-dimensional geometric analysis (3DGA)

Database management (DBM)

Computer graphics display facilities (GCDF)

Peripheral control function (PFC)

Design analysis modules (DAM)

2,300

5,300

6,800

3,350

4,950

2,100

8,400

TOTAL 33,200

ESTIMATED LOC = (S optimistic + 4*S moderate +S pessimistic) / 6

TOTAL PROJECT COST = $431,000 (54 person-month)Productivity=620 LOC/pm Salary=$8,000 Cost/LOC=$13

FP-BASED ESTIMATION IFP-BASED ESTIMATION IInformation domain Opt

.Likely Pess. Est.

CountWeight FP

Count

Number of inputs

Number of outputs

Number of inquiries

Number of files

Number of external interfaces

20

12

16

4

2

24

15

22

4

2

30

22

28

5

3

24

16

22

4

2

4

5

4

10

7

97

78

88

42

15

Count Total 320

FP Count = Weight * (FP optimistic + Weight*FP likely + FP pessimistic) / (Weight +2)

FP estimated = Count Total * [0.65 + 0.01 * Σ(Fi)] = 375

TOTAL PROJECT COST = $461,000 (58 person-month)Productivity=6.5 FP/pm Salary=$8,000 Cost/FP=$1,230

FP-BASED ESTIMATION IIFP-BASED ESTIMATION II

Factor Value (Fi)Backup and recovery 4Data communication 2Distributed processing 0Performance critical 4Existing operating environment 3On-line data entry 4Input transaction over multiple screen 5Master files updated on-line 3Information domain values complexity 5Internal processing complexity 5Code design for reuse 4Conversion/installation in design 3Multiple installation 5Application designed for change 5Complexity adjustment factor 1.17

HISTORICAL PROJECT METRICS

HISTORICAL PROJECT METRICS

Project Type:Product: requirements from marketCustomized: RFP and proposalSystem Integration: RFP and proposal

• Previous methods only estimate coding, not requirement, design, documentation, etc.

• Use historical project data (similar projects, metrics)• 20 LOC/day (…), simple but efficient, hourly price of engineer (head

count cost) including management cost + travel cost + per dine • Requirement collection + analysis = implementation• Product size estimation: brainstorm and bi-weekly estimation• Type of projects: Cost + profit, Fixed price• Difficult to estimate scope during bid process, to get the project, cut

price and under estimate• Application domain knowledge expertise

ACTIVITY SEQUENCINGACTIVITY SEQUENCING

PROJECT NETWORK DIAGRAM: a schematic display of the logical relationships among, or sequencing of, activities.

• Arrow diagramming method (ADM)

• Precedence diagramming method (PDM)

ADMActivity-On-Arrow (AOA)

ADMActivity-On-Arrow (AOA)

1

2

3

4

5

6

7

8

A=1

B=2

C=3

D=4

E=5

G=6

F=4

H=6

I=2

J=3

Critical Path (B-E-H-J) Is the series of activities that determine the earliest time by which the project can be completed. It is the longest path through the network diagram and has the least amount of slack (not the shortest path in the domain of transportation)

BurstBurst

Merge

Merge

Activity-On-Arrow (AOA)Activity-On-Arrow (AOA)

A=1

B=2

C=3

D=4

E=5

G=6

F=4

H=6

I=2

J=31

2

3

4

5

6

7

8

TASK SLACK

A 2

B 0

C 2

D 2

E 0

F 7

G 2

H 0

I 2

J O

5: A-D=5; B-E=76: A-D-H=11; B-E-H=13; B-F=6; C-G-I=11

DUMMY ACTIVITYDUMMY ACTIVITY

1

2

3

4

5

6

7

10

A=1

B=2

C=3

D=4

E=5

G=6

F=4

H=6

I=2

J=3

8

K=11

9L=1

Critical Path Method (CPM)

Dummy activity

PDMPDM

A

B

A

B

A

B

A

B

Finish-to-start (FS)Task B cannot start until task A finishes

Start-to-start (SS)Task B cannot start until task A starts

Finish-to-finish (FF)Task B cannot finish until task A finishes

Start-to-finish (SF)Task B cannot finish until task A starts

A

Start:

Finish:

ID: 1

C

Start:

Finish:

ID: 3

D

Start:

Finish:

ID: 4

E

Start:

Finish:

ID: 5

B

Start:

Finish:

ID: 2

A

B

C

D

E

F

G

H

I

J

S M T W T F S S M T W T F S S M T W T F S S M

Gantt ChartGantt Chart

Techniques for shortening scheduleTechniques for shortening schedule

• Crashing: making cost and schedule trade-offs to obtain the greatest amount of schedule compression for the least incremental cost.

1 2 3

1

3a

43b

3c

2

A=5 B=9

A=5

B1=4

B2=3

B3=2

B1’=1

B3’=2

In preparing critical path diagram for a project, usually resource is not considered. You may have to consider resources when shortening schedule.

Techniques for shortening scheduleTechniques for shortening schedule

• Fast tracking: doing activities in parallel that you would normally do in sequence.

1 2 3

1

3

4

2

A=5 B=9

A’=0

B=9

C=6

4C=6

A=5

CRITICAL CHAIN SCHEDULINGCRITICAL CHAIN SCHEDULING• Avoid multitaskingMultitasking: when a resource works on more than one task/project at a time.

TASK 1 TASK 3

10 days 10 days

Task 2completed

Task 3completed

Task 1 Task 2 Task 3 Task 1 Task 2 Task 3

10 days

5 days 5 days 5 days 5 days 5 days 5 days

Task 1completed

Task 2completed

Task 3completed

+△ +△ +△

TASK 2

Task 1completed

CRITICAL CHAIN SCHEDULINGCRITICAL CHAIN SCHEDULING• Avoid individual bufferIndividual buffers: when activity duration estimations are done by individuals,

safety (buffer) is usually included for each estimation.

FB

FB

FB

Proj. buffer

Add project buffer and feeding buffer (FB)

CRITICAL CHAIN SCHEDULINGCRITICAL CHAIN SCHEDULING

• Probabilistic time estimates

Optimistic time + 4xmost likely time + pessimistic time=

6

Weighted average