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© T.P. Rout and Griffith University, 1996

A Unified Reference Model for the Processes of Software and

System Life Cycles

Terry Rout

Software Quality Institute

Griffith University

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© T.P. Rout and Griffith University, 1996

SC7 Life Cycle Standards

Processes for the Product Life Cycle: ISO/IEC 12207 - 1995: Software Life Cycle Process ISO/IEC TR 15504 - 1998: Software Process Assessment WD 15288: Systems Life Cycle Processes

Individual Life Cycle Processes: WD 15939 - Software Measurement Process ISO/IEC 14598: 1998 - Software Product Evaluation Standards for:

Software Maintenance Configuration Management Project Management

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© T.P. Rout and Griffith University, 1996

The Current Situation: Confusion

12207 - Processes defined through prescribed sets of activities and tasks

15504 - Processes described through purpose statement and description of outcomes of implementation

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© T.P. Rout and Griffith University, 1996

ISO 12207 - Software Life Cycle Processes

PRIMARY PROCESSESPRIMARY PROCESSES SUPPORTING PROCESSESSUPPORTING PROCESSES

ORGANISATIONAL PROCESSESORGANISATIONAL PROCESSES

Acquisition

Supply

Development

Operation

Maintenance

Documentation

Configuration Management

Problem Resolution

Management

Improvement

Infrastructure

Training

Quality AssuranceVerificationValidationJoint ReviewAudit

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© T.P. Rout and Griffith University, 1996

ISO 15504 - The Process Dimension

PRIMARY PROCESSESPRIMARY PROCESSES SUPPORTING PROCESSESSUPPORTING PROCESSES

ORGANISATIONAL PROCESSESORGANISATIONAL PROCESSES

Documentation

Configuration Management

Problem Resolution

Quality AssuranceVerificationValidationJoint ReviewAudit

AcquisitionAcquisition PreparationSupplier selectionSupplier managementCustomer acceptance

Supply

OperationSystem operationCustomer support

Requirements elicitation

DevelopmentSystem analysis and designSoftware requirements analysisSoftware designSoftware implementationSoftware integrationSoftware testingSystem integration and testing

Maintenance

Management

Quality Management

Risk Management

ImprovementProcess establishmentProcess assessmentProcess improvement

Organisational alignment Infrastructure

Human Resource ManagementProject Management

Reuse

Measurement

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© T.P. Rout and Griffith University, 1996

The Way Forward: Agreement

Processes will be described in terms of purpose and outcomes

12207 will additionally define activities and tasks for recommended / desired implementation

15504 will define a scale for measurement / evaluation of capability

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© T.P. Rout and Griffith University, 1996

Process Outcomes

Ideally, each outcome would have the following characteristics: capability-neutral (“capability” is used here in the sense of

15504) role-independent (“role” is explained later) succinct not a restatement or functional decomposition of the purpose phrased in terms of a continuing responsibility to:

(1) produce and maintain an artifact; (2) achieve and maintain a state; or (3) meet a constraint.

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© T.P. Rout and Griffith University, 1996

Identifying Processes

Desirable characteristics for processes include: Consistent with each other Autonomous Non-overlapping Cohesive Low coupling with other processes Cover the existing set of standards

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© T.P. Rout and Griffith University, 1996

Process Model for

Software and System Life

Cycles

Requirements for

implementing Software Life

Cycle Processes

Requirements for

implementing System Life

Cycle Processes

Requirements for performing

Process Assessments

invokes by reference

invokes by reference

invokes by reference

Relationship of Life Cycle Standards

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© T.P. Rout and Griffith University, 1996

What is missing?

The current proposal within SC7 is for a list of “defined” processes only

There is no architecture established that describes the relationships between processes

To ignore these relationships can only in the long term lead to confusion

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© T.P. Rout and Griffith University, 1996

A proposal for a reference process architecture

Separation of product life cycle from enterprise-driven “sustaining” processes.

A classification of the “sustaining” processes drawn from, but not identical to, 12207 and 15504.

The concept – embodied in 15504 – that processes may contain other (“component” or “subsidiary”) processes within their scope.

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© T.P. Rout and Griffith University, 1996

GERAM: Four essential view types and their contents

design

identification

concept

requirements

implementation

operation

decommission

ResourceOrganisation

InformationFunction

life-cyclestages

model contentviews

purpose views task views Manifestationviews

Product,Cust. Service

Mgmt,Control

Hard-wareSoft-ware

TechnologyTasks

HumanTask

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© T.P. Rout and Griffith University, 1996

Product Life Cycle Processes

Product Identification Process Product Concept Derivation Process Product Requirements Definition Process Product Design Process Product Implementation Process Product Operation Process Product Decommissioning Process

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© T.P. Rout and Griffith University, 1996

Sustaining Life Cycle Processes

Commercial Processes Project-Oriented Processes Organizational Processes