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SEI Capability Maturity Model

Advanced Software Engineering

COM360University of Sunderland © 2000

SEI CMM

What is the CMM (I)?...

‘The CMM is a 5-level model where each maturity level is “a well-defined evolutionary plateau on the path towards becoming a mature software organisation”.’ SEI

( - translate please!)

SEI CMM

What is the CMM (II)?...

‘The CMM provides a conceptual

structure for improving the management

and development of software products in a

disciplined and consistent way.’ SEI

(process vs. product?)

Software Measurement

SEI CMM Levels

REPEATABLE

INITIAL

DEFINED

MANAGED

OPTIMISING

discipline

standard,consistent

predictable

continuousimprovement

project management

engineering management

quantitative management

changemanagement

SEI CMM

The CMM Structure

Maturity levels

Key Process Areas

Implementation / institutionalisation

Infrastructureor activities

Common Features

Key Practices

Process capability

Goals

contain

organised by

contain

indicate

achieve

address

describe

SEI CMM

Applying the CMM

• Self assessmentpossible because the CMM document t is detailed,cheaper to do in-house, lack of experience/independence

• Formal assessmentindependent and experienced, identifies improvement priorities

• Software Capability Evaluationto identify qualified contractors

Software Measurement

Assessment Steps Team selection

small, qualified team chosen; as independent as possible

Maturity questionnairesample of depts/projects is questioned; results are analysed for further investigation/clarification

Site visitactual depts/projects visited; interviews conducted, documents reviewed, priority process areas scrutinised

Presentation of findings to management2 parts - CMM assessment of current level of org., identify strengths & weaknesses and key improvement areas

SEI CMM

ISO9000 and CMM comparedCMM ISO 9001 (9000-3)

• Specific to software development Intended for most industries

• Used in USA, less widely Recognised and accepted in most elsewhere countries

• Provides detailed and specific Specifies concepts, principles and definition of what is required safeguards that should be in place for given levels

• Assesses on 5 levels Establishes one acceptable level

• CMM Level 2 - 3 ISO 9001 (9000-3)

• Relevant to Stabilises the customer - supplier s/w development process relationship

• No time limit on certification Certification valid for three years

• No ongoing audit Auditors may return for spot checks during the lifetime of the certificate

SEI CMM

Critical Evaluation (I)...• Best practice - as defined by who, when,

- with respect to what development types, what application areas, which tools?

• Management and process discipline- vs. what made the software good and how produced

• Is the CMM maturity scale really ordinal -are all activities at level n+1 dependent on those at n?

• Are the levels “clear evolutionary plateaus” -e.g. measurements are essential to project tracking and quality assurance (L2), but the KPA of quantitative process mngmt = measurement (L4)

SEI CMM

Critical Evaluation (II)...• Scoring -

CMM employs a multi-hurdle system; questions and ‘key questions’

• Sparse data sets -approx. 100 questions to cover everything in a software development process

• Number vs. Profile - the number is mesmerising, but the profile is the instructive outcome

SEI CMM

A Final Word “There are serious measurement questions... We must

ensure that the models are appropriate (see Ch. 2 of

Software Metrics) .... We must understand how reliable

and valid measurements and models are. We must

know what entities are being measured, and we must

test the relationships between the maturity scores and

the behaviours that ‘maturity’ is supposed to produce

or enhance.” Fenton & Pfleeger, Software Metrics, Edn. 2 , 1997