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Project Management

Project Management Activities

Project Scheduling

Cost Estimation

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Project Management Activities

Project acquisitionProject planningo Resource assessmento Risk and option analysis

Cost estimationProject schedulingo Work breakdown structureo Effort distributiono Resource assignment

Project tracking and controlReporting

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Project Resources

Peopleo Required skillso Availabilityo Duration of taskso Start date

Hardware and software toolso Descriptiono Availabilityo Duration of useo Delivery date

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Risk Analysis

What is a risk?

Risk impact: the loss associated with the eventRisk probability: the likelihood that the event will occurRisk control: the degree to which we can change the outcome

Risk exposure = (risk probability) x (risk impact)

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Top Ten Project RisksStaff deficienciesUnrealistic schedules and budgetsDeveloping the wrong functionsDeveloping the wrong interfaceOver-engineeringChanging requirementsExternally developed itemsExternally performed tasksPerformance problemsAssumptions on technology

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Define Work Breakdown Structure

Activityo Major work unito Start date o End dateo Consumes resourceso Results in work

products (and milestones)

Project

Phase 1

Phase 2

Phase N

Step 1

Step 2

Step 1

Step 2

Step 1

Step 2

Activity 1Activity 2Activity 3

Activity 1Activity 2 Task 1

Task 2Task 3

Project functiono Continue

throughout the project

o Not bound to specific phases

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Schedule Activities

Almost all activities depend on the completion of some other activitiesMany activities can be performed in parallelOrganisation necessary to balance work-load, costs, and durationo PERT chart (activity network/task graph)

Critical pathProject Time-line (Gantt chart)Resource table

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PERT Charts

Program Evaluation and Review TechniqueGrapho Nodes = activities/tasks and estimated durationo Edges = dependencies

Computeo Slack time = available time - estimated durationo Critical path

A path is critical when it contains an activity that, if delayed, will cause a delay of the whole project.

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Example PERT Chart

Design electrical andpneumatic renovations

4 4d

5/4/00 5/9/00

Schedule down-time withproduction supervisor

5 2d

5/10/00 5/11/00

Renovate electrical andpneumatic

13 2d

5/17/00 5/18/00

Get final report from PSU

1 5d

4/27/00 5/3/00

Schedule contractor forelectrical and pneumatic

8 1d

5/12/00 5/12/00

InformPSUabout pickup

7 2d

5/5/00 5/8/00

Removeold hardware

11 2d

5/15/00 5/16/00

Shut down production line

10 1d

5/12/00 5/12/00

Install new hardware

14 3d

5/19/00 5/23/00

Schedule truck to pickuphardware at PSU

6 1d

5/4/00 5/4/00

Get blueprints for oldhardware

2 1d

4/27/00 4/27/00

Time-motionstudy ofexisting hardware

3 2d

5/4/00 5/5/00

Store old hardware (justin case)

12 10d

5/17/00 5/30/00

Transport hardware fromPSU

9 2d

5/9/00 5/10/00

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Gantt charts

A Gantt chart is used to graphically present the start and end dates of each software engineering task o One axis shows time.o The other axis shows the activities that will be

performed.o The black bars are the top-level tasks. o The white bars are subtaskso The diamonds are milestones:

• Important deadline dates, at which specific events may occur

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A Gantt Chart (Project Time Line)

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Another Gantt Chart

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Cost Estimation

Approacho Decompose problemo Check for experiences/

data on sub problemso Make qualified

estimationso (Make at least two

independent estimates)

Problems:o What are good measures?o Do the estimates affect the

result?o Does the type of software

affect the result?o Does the project environment

affect the result?o ...

Use empirical and historical dataAlgorithmic cost modelling

COCOMO (based on LOC) FP (based on function points)

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COCOMOConstructive Cost Modelling [Boehm 81]Based on publicly available historical data of 63 TRW projectsBasic assumptions:o Requirements change only slightly during the

projecto There is good project managemento The historical data is representativeo Assigning more resources to the project does NOT

result in linear decreasing development time

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Large and inexperienced teams, many constraints

a b c d

2.4

3.0

3.6

1.05

1.12

1.20

2.5

2.5

2.5

0.38

0.35

0.32

Boehm, Software Engineering Economics, Prentice-Hall, 1981.

Basic Model

•KDSI = Kilo Delivered Source Instructions ( LOC - comments)•The a, b, c, and d factors vary depending on the type of project•Effort is measured in PM (Person Months = 152h of work)•Schedule is the Development Time measured in Months

Organic

Semi-detached

Embedded

In-house IS, Development in a familiar environment

Between OM- and EM projects

Effort = a (KDSI)b Schedule = c (Effort)d

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COCOMO Summary

Works quite well in practiceNeeds KLOC as inputProblems:o Estimating KLOC in early project stages o Comparison of projects using different LOC countso Outdated metrics base (70s)

Solutions:o Cross-check using an other estimation techniqueo Standardised LOC countso Continuous model calibration

COCOMO II is a recent new version

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COCOMO II

Goal: To develop a software cost and schedule estimation model tuned to the life cycle practices of the 1990’s and 2000’s

3 Modelso Application Composition: prototyping to resolve high-

risk user interface issues, 2 environment drivers, 0 process drivers, Sizing in Object Points

o Early Design Model: to explore alternative architectures and concepts,7 environment drivers, 5 process drivers, Sizing in Function Points or SLOC

o Post Architecture Model: development has begun, 17 environment drivers, 5 process drivers, Sizing in Function Points or SLOC

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FactorsScaleProcessSizeEffort Multiplier

s

Environment

FactorsScaleProcess EffortSchedule Multiplier

Effort and schedule in COCOMO 2

• Environment: product, platform, people, project factors

• Process: constraint, risk/architecture, team, maturity factors

Effort = NOP/productivity NOP = OP * [(100 -%reuse)/100] Productivity = NOP/man-months, 5 productivity levels

depending on the 2 environment drivers (table 3.12 course book)

Early Design and Post-architecture Model

Application Composition Model

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Feasibility

Concept ofOperation

Rqts.Spec.

Plansand

Rqts.

ProductDesign

ProductDesignSpec.

DetailDesignSpec.

DetailDesign

Devel.and Test

AcceptedSoftware

Phases and Milestones

RelativeSize Range x

4x

2x

1.25x

1.5x

0.25x

0.5x ApplicationsComposition

(3 parameters)

Early Design(13 parameters)

Post-Architecture(23 parameters)0.67x

0.8x

COCOMO II Model Stages

Overestimated

Underestimated

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COCOMO II summary

COCOMO II +allow for spiral model instead of waterfall

model only+Size of project can be listed as object

points, function points or source lines of code (SLOC)

+The environmental multipliers are calculated from seventeen cost drivers better suited for today's methods

- Calibration is difficult, but can improve accuracy by a factor of five

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Function PointsFunction Point Analysis (FPA) measures the size of a software product in terms of the functionality it delivers to the users. A.J. Albrecht 1979o What the software must do from the user’s perspectiveo Irrespective of software construction

Based on five function types:o Inputso Outputso Inquirieso Logic Fileso Interfaces

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Project plan contents

Project scopeProject scheduleProject team organizationTechnical description of systemProject standards and proceduresQuality assurance planConfiguration management plan

Documentation planData management planResource management planTest planTraining planSecurity planRisk management planMaintenance plan

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Difficulties and Risks in Project Management

Accurately estimating costs is a constant challengeIt is very difficult to measure progress and meet deadlines It is difficult to deal with lack of human resources or technology needed to successfully run a projectCommunicating effectively in a large project is hard It is hard to obtain agreement and commitment from others