Software Quality Matters

 

Ronan FitzpatrickSchool of Computing

Dublin Institute of Technology

Outline

Definitions, models and standards The Software Quality Star Perspectives of software quality Strategic drivers of software

quality

Objective

To provide an introduction to the issues that impact software quality as seen through the eyes of a software quality assurance manager.

Definitions

Fitness for purpose Compliance with specification

A measure of excellence measure Low quality, high quality excellence the presence of product

attributes

Definitions of software quality - 1

German Industry Standard DIN 55350 Part 11

Quality comprises all characteristics and significant features of a product or an activity which relate to the satisfying of given requirements.

ANSI Standard (ANSI/ASQC A3/1978) Quality is the totality of features and characteristics of a

product or a service that bears on its ability to satisfy the given needs.

ISO/IEC 9126 (1991) The totality of features and characteristics of a software

product that bear on its ability to satisfy stated or implied needs.

Definitions of software quality - 2

IEEE Standard (IEEE Std 729-1983) The totality of features and characteristics of a

software product that bear on its ability to satisfy given needs: for example, conform to specifications.

The degree to which software possesses a desired combination of attributes.

The degree to which a customer or user perceives that software meets his or her composite expectations.

The composite characteristics of software that determine the degree to which the software in use will meet the expectations of the customer.

Shortcommings of these definitions

Focus only on product attributes or characteristics and to a lesser degree on use

Do not consider the potential to achieve quality through best practice

Management, development, staffing, operations

Models

The House of Quality

Standards

ISO/IEC 12207(1995)

Software Quality Star

Copyright 2000 © Ronan Fitzpatrick

QualitySTAR

Contract

Project

Process

Producer Procurer

Product

User

ISProfessional

Perspectives of software quality

The Product perspective Quality attributes

The Contract perspective Quality assurance review and planning

The Supplier (producer) perspective Producer, project and process

The Acquirer (procurer) perspective Procurer, IS professional and user

The product perspective

EXTERNAL QUALITY FACTORS

INTERNAL QUALITY

FACTORS

STRATEGIC QUALITY

FACTORS

CORE QUALITY

FACTORS

Suitability Installability Functionality Adaptability Ease-of-use Learnability

Interoperability Reliability Safety Security Correctness Efficiency

Maintainability Testability Flexibility Reusability Portability

DOMAIN-SPECIFIC QUALITY

FACTORS

Visibility Intelligibility Credibility Engagibility

Differentiation

The contract perspectiveQuality assurance planning per ISO/IEC 12207 (1995)

Quality standards, methodologies, procedures, and tools for performing the quality assurance activities (or their references in organisation’s official documentation)

Procedures for contract review and coordination thereof

Procedures for identification, collection, filing, maintenance and disposition of quality records

Resources, schedule, and responsibilities for conducting the quality assurance activities

Selected activities and tasks from supporting processes, such as Verification (6.4), Validation (6.5), Joint Review (6.6), Audit (6.7), and problem Resolution (6.8).

The supplier perspective

Producer

Project

Process

The supplier perspectiveProducer

Enlightened philosophy and leadership

Employing first-rate staff Who engage in first-rate processes Using first-rate tools and

techniques To create quality software

products

The supplier perspective Project

ISO 12207 (1995) onus on supplier to develop and document project management plans implement and execute the project management plans

Project management planning issues are 1.     Organisation and environment 2.     Acquirer involvement 3.     Acquirer requirements and quality characteristic 4.     WBS, resources and contractors 5.     Quality assurance/validation and verification 6.     Risk management 7.     Licensing, usage and ownership 8.     Tracking, documenting and reporting 9.     Personnel training

Planning quality detail

Acquirer requirements and quality characteristics

define their quality requirements and quantify the quality

characteristics of the software product

Quality assurance/validation and verification

item testing, integration testing, system testing and acceptance testing

Capability Maturity Model

People P-CMM

Other issues Schedule Budget

The supplier perspective Process

Life cycle processes per ISO/IEC 12207

Capability Maturity Model SPICE ISO 9001 certification

Life cycle processes

6.3 Quality Assurance

1. Process implementation – requires that a quality assurance process tailored to the project should be established

2. Product assurance – requires that plans and procedures be established to ensure that the software product meets the requirements specification

3. Process assurance – requires that the life cycle processes used by the supplier organisation comply with the contract

4. Assurance of quality systems – requires that the ISO 9001 quality management activities are assured.

Capability Maturity Model

SW-CMM

The acquirer perspective

Procurer

IS professional

User

The acquirer perspective Procurer

Can be supported by the IS professionals Will be acceptable to the user community

Also, but not addressed by ISO/IEC 12207 Provides some form of competitive advantage Value for money Complies with any legal obligations Matched current business processes

The acquirer perspective IS professional

Advise to management regarding the specification

Technical excellence, user empowerment, corporate alignment, investment efficiency, supplier organisation

profile.

Perspective is influenced by role viz, development professional or support

professional

The acquirer perspective User - usability

Product-centred view of usability: that the usability of a product is the attributes of the product

which contribute towards the quality-of-use.

Context-of-use view of usability: that usability depends on the nature of the user, product,

task and environment.

The quality-of-use view of usability: that usability is the outcome of interaction and can be measured by

the effectiveness, efficiency and satisfaction with which specified users achieve specified goals in particular environments.

Strategic drivers of software quality

Perspectives of the Software Quality Star are derived from the contracting arrangement of ISO/IEC 12207.

Does not consider all the strategic business issues of either the acquirer or the supplier.

Solution is a new Software Quality Strategic Driver Model.

Corporatealignment

Technicalexcellence

Useracceptance

Investmentefficient

Competitivesupport

Statutoryconformance

Corporateaccreditation

Qualitymanagement

Software Quality – Strategic Driver Model

Copyright © 2000 Ronan Fitzpatrick

Domainspeciality

Competitiveexcellence

Developmentexcellence

QualitySTAR

Contract

Project

Process

Producer Procurer

Product

User

ISProfessional

Strategic Driver Model

Can it be developed further This research developed SQ-SDM

Is there potential to adapt the model for Network Management NM-SDM e-Commerce eCom-SDM Customer Relationship Management CRM-SDM and similar

Conclusion

Definitions, models and standards Definitions are not fully accurate

The Software Quality Star Based on ISO/IEC 12207 (1995)

Perspectives of software quality Contract, supplier, product and acquirer

Strategic drivers of software quality

Procurer perspective Producer perspective