© Pearson Education Limited 2004

OHT 9.1

Cadle and Yeates: Project Management for Information Systems, 4th edition

IS estimating issues

• Unique projects with much innovation

• “Estimates” often produced early – before specification agreed

• No professional estimators

• Few published metrics available

© Pearson Education Limited 2004

OHT 9.2

Cadle and Yeates: Project Management for Information Systems, 4th edition

Analogy method

• Find a similar project:– Type of business– Size of applications– Scope of systems– Technical methods and standards

• Must adjust for:– Organisational culture– Users’ level of computer literacy– Degree of management support for project

© Pearson Education Limited 2004

OHT 9.3

Cadle and Yeates: Project Management for Information Systems, 4th edition

Analysis and programming approaches

• Explicitly estimate for one stage:– Analysis method – analysis stage– Programming method – code/unit test stage

• Extrapolate whole project outcome from stage estimate

• Must adjust for:– Project size– Familiarity with business and technical environment– Technical complexity

© Pearson Education Limited 2004

OHT 9.4

Cadle and Yeates: Project Management for Information Systems, 4th edition

Direct estimate (from project breakdown)

• Break down project (either using WBS or PBS approach)

• Estimate for each task / product

• Sum products to get stages

• Sum stages to get project

• Takes time…

• …and requires expert estimators

© Pearson Education Limited 2004

OHT 9.5

Cadle and Yeates: Project Management for Information Systems, 4th edition

Delphi technique

• Several estimators given specification of work and asked for estimates

• Summarised anonymously and results circulated to estimators

• Can revise estimates in the light of others’ ideas

• Method reduces personal disagreements and ego-based issues

© Pearson Education Limited 2004

OHT 9.6

Cadle and Yeates: Project Management for Information Systems, 4th edition

CoCoMo

• Formulae based on thousands of delivered source instructions (KDSI)

• Basic, intermediate and detailed versions

• CoCoMo II now developed for wider range of development approaches

• Useful elapsed time formula:

2.5 x (estimated effort in man-months)0.33

© Pearson Education Limited 2004

OHT 9.7

Cadle and Yeates: Project Management for Information Systems, 4th edition

Function point analysis

• Based on analysis of inputs, outputs and files accessed in system

• Starts with unadjusted function points

• Then adjusts for:– technical complexity– performance-influencing factors– risks

© Pearson Education Limited 2004

OHT 9.8

Cadle and Yeates: Project Management for Information Systems, 4th edition

Supporting activities

• Can considerably inflate base estimates• Includes:

– Proportional activities:• Team leading/supervision• Documentation• Quality control• Customer reviews

– Elapsed-time activities:• Project management• Systems management• Configuration management• Project office work