software quality requirements and evaluation

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Software QualityRequirements And Evaluation

Created by: Thao Mai-Thi-Bich

Effective date: December 08, 2012

Version: 1.0

Template ID: N/A

Software Quality Requirements & Evaluation 2

Document ControlVersion Change description Changed by Date Approved by Date

0.1 Initiate Thao Mai-Thi-Bich November 29, 2012 N/A N/A

1.0 Format update Nhuan Lai-Duc December 08, 2012 Nhuan Lai-DucDecember 08, 2012


Review RecordVersion Defects Type Severity Reviewed by Date

0.1 Format W Minor Nhuan Lai-Duc December 08, 2012

Types:

A – Ambiguous (something described unclearly, unintelligibly)

M – Missing (something needs to be there but is not)

W – Wrong (something is erroneous with something else)

E – Extra (something unnecessary is present)

Severity:

Fatal, Major, Minor, Cosmetic


Agenda

Organization Of SQuaRE Series Of International Standards

1

Targets Of Quality Models 3

Structure Used For The Quality Models2

Product Quality Model 4

Quality In Use Model 5

Data Quality Model 6


Agenda







1



Figure 1 — Organization of SQuaRE series of International Standards



ISO/IEC 2500n - ISO/IEC 2500n - Quality Management Quality Management

DivisionDivision

● Define all common models, terms and definitions

● Provides requirements and guidance for a supporting

function that is responsible for the management of the

requirements, specification and evaluation of software

product quality.

ISO/IEC 2501n - ISO/IEC 2501n - Quality Model DivisionQuality Model Division

● Present detailed quality models for computer systems

and software products, quality in use, and data

● Practical guidance on the use of the quality models



ISO/IEC 2502n -ISO/IEC 2502n -Quality Measurement Quality Measurement

DivisionDivision

ISO/IEC 2503n - ISO/IEC 2503n - Quality Requirements Quality Requirements

DivisionDivision

● Include a software product quality measurement

reference model, mathematical definitions of quality

measures, and practical guidance for their application

● Help specify quality requirements, based on quality

models and quality measures.

● These quality requirements can be used in the

process of quality requirements elicitation for a

software product to be developed or as input for an

evaluation process.


ISO/IEC 2504n - ISO/IEC 2504n - Quality Evaluation Quality Evaluation

DivisionDivision


● Provide requirements, recommendations and

guidelines for software product evaluation, whether

performed by evaluators, acquirers or developers


Agenda


1







Structure Used For The Quality Models


Agenda


1







Targets Of Quality Models


Agenda


1







Product Quality Model



Product quality model What It MeansFunctional suitability

Functional completeness Degree to which the set of functions covers all the specified tasks and user objectives

Functional correctness

Performance efficiency Performance relative to the amount of resources used under stated conditions

Time behaviour

Resource utilization

Capacity

Degree to which a product or system provides functions that meet stated and implied needs when used under specified conditions

Degree to which a product or system provides the correct results with the needed degree of precision

Functional appropriateness

Degree to which the functions facilitate the accomplishment of specified tasks and objectives

Degree to which the response and processing times and throughput rates of a product or system, when performing its functions, meet requirements

Degree to which the amounts and types of resources used by a product or system when performing its functions meet requirements

Degree to which the maximum limits of a product or system parameter meet requirements



Product quality model What It MeansCompatibility

Co-existence

Interoperability

Degree to which a product, system or component can exchange information with other products, systems or components, and/or perform its required functions, while sharing the same hardware or software environment

Degree to which a product can perform its required functions efficiently while sharing a common environment and resources with other products, without detrimental impact on any other product

Degree to which two or more systems, products or components can exchange information and use the information that has been exchanged



Product quality model What It MeansUsability

Learnability

Operability Degree to which a product or system has attributes that make it easy to operate and control

Performance efficiency Performance relative to the amount of resources used under stated conditions

Time behaviour

Resource utilization

Capacity Degree to which the maximum limits of a product or system parameter meet requirements

Degree to which a product or system can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use

Appropriateness recognizability

Degree to which users can recognize whether a product or system is appropriate for their needs

Degree to which a product or system can be used by specified users to achieve specified goals of learning to use the product or system with effectiveness, efficiency, freedom from risk and satisfaction in a specified context of use

Degree to which the response and processing times and throughput rates of a product or system, when performing its functions, meet requirements

Degree to which the amounts and types of resources used by a product or system when performing its functions meet requirements



Product quality model What It MeansReliability

Maturity Degree to which a system meets needs for reliability under normal operation

Availability

Fault tolerance

Recoverability

Degree to which a system, product or component performs specified functions under specified conditions for a specified period of time

Degree to which a system, product or component is operational and accessible when required for use

Degree to which a system, product or component operates as intended despite the presence of hardware or software faults

Degree to which, in the event of an interruption or a failure, a product or system can recover the data directly affected and re-establish the desired state of the system



Product quality model What It MeansSecurity

Confidentiality

Integrity

Non-repudiation

Accountability Degree to which the actions of an entity can be traced uniquely to the entity

Authenticity

Degree to which a product or system protects information and data so that persons or other products or systems have the degree of data access appropriate to their types and levels of authorization

Degree to which a product or system ensures that data are accessible only to those authorized to have access

Degree to which a system, product or component prevents unauthorized access to, or modification of, computer programs or data

Degree to which actions or events can be proven to have taken place, so that the events or actions cannot be repudiated later

Degree to which the identity of a subject or resource can be proved to be the one claimed



Product quality model What It MeansMaintainability

Modularity

Reusability

Analysability

Modifiability

Testability

Degree of effectiveness and efficiency with which a product or system can be modified by the intended maintainers

Degree to which a system or computer program is composed of discrete components such that a change to one component has minimal impact on other components

Degree to which an asset can be used in more than one system, or in building other assets

Degree of effectiveness and efficiency with which it is possible to assess the impact on a product or system of an intended change to one or more of its parts, or to diagnose a product for deficiencies or causes of failures, or to identify parts to be modified

Degree to which a product or system can be effectively and efficiently modified without introducing defects or degrading existing product quality

Degree of effectiveness and efficiency with which test criteria can be established for a system, product or component and tests can be performed to determine whether those criteria have been met



Product quality model What It MeansPortability

Adaptability

Installability

Replaceability

Degree of effectiveness and efficiency with which a system, product or component can be transferred from one hardware, software or other operational or usage environment to another

Degree to which a product or system can effectively and efficiently be adapted for different or evolving hardware, software or other operational or usage environments

Degree of effectiveness and efficiency with which a product or system can be successfully installed and/or uninstalled in a specified environment

Degree to which a product can be replaced by another specified software product for the same purpose in the same environment


Agenda


1







Quality In Use Model



Quality in use model What It MeansEffectiveness Accuracy and completeness with which users achieve specified goals

Efficiency

Satisfaction

Usefulness

Trust

Pleasure Degree to which a user obtains pleasure from fulfilling their personal needs

Comfort Degree to which the user is satisfied with physical comfort

Resources expended in relation to the accuracy and completeness with which users achieve goals

Degree to which user needs are satisfied when a product or system is used in a specified context of use

Degree to which a user is satisfied with their perceived achievement of pragmatic goals, including the results of use and the consequences of use

Degree to which a user or other stakeholder has confidence that a product or system will behave as intended


Quality in use model What It Means

Economic risk mitigation

Environmental risk mitigation

Context coverage

Context completeness

Flexibility

Freedom from risk Degree to which a product or system mitigates the potential risk to economic status, human life, health, or the environment

Degree to which a product or system mitigates the potential risk to financial status, efficient operation, commercial property, reputation or other resources in the intended contexts of use

Health and safety risk mitigation

Degree to which a product or system mitigates the potential risk to people in the intended contexts of use

Degree to which a product or system mitigates the potential risk to property or the environment in the intended contexts of use

Degree to which a product or system can be used with effectiveness, efficiency, freedom from risk and satisfaction in both specified contexts of use and in contexts beyond those initially explicitly identified

Degree to which a product or system can be used with effectiveness, efficiency, freedom from risk and satisfaction in all the specified contexts of use

Degree to which a product or system can be used with effectiveness, efficiency, freedom from risk and satisfaction in contexts beyond those initially specified in the requirements



Agenda


1







Data Quality Model


Data Quality Model

Consistency The absence of apparent contradictions within data Inconsistency can be verified on the same or different entities Example: An employee's birth date cannot be later than his

“recruitment date” Currency

Currency is the extent to which data is up-to-date It is critical for volatile data (Ex: frequently updated data, as wind

speed or climate temperature) Example 1: When attending a course, a student needs to know

the right timetable before its starting date

Example 2: A flight seat cannot be available after it has been

assigned to someone; so the flight seat data value must be stored

before another user asks for the same data


Completeness From a computer system's point of view

The extent to which all necessary values have been assigned

and stored in the computer system Refers both to entity occurrences and to attributes of a single

occurrence From an end-user perspective

The extent to which data are sufficiently able to satisfy user's

stated needs from quantitative point of view Includes also the capability of data to represent the context

observed by users Example: if an entity refers to a company's employees, all the

employees must be recorded with all attributes requested to

satisfy a user's stated needs

Data Quality Model


Precision The capability of the value assigned to an attribute to provide the

degree of information needed in a stated context of use

Example: to represent the duration of a marathon race the

minimum unit of time must be seconds; to represent the duration

of 100 meters race the minimum unit of time must be milliseconds

Accuracy The degree to which a data value conforms to its actual or

specified value

Data Quality Model


Accuracy: Two main aspects Syntactical accuracy

The closeness of the data values to a set of values defined in a domain considered syntactically correct

Example: a low degree of syntactical accuracy is when the word Mary is stored as Mary

Semantic accuracy

Semantic accuracy is defined as the closeness of the data values to

a set of values defined in a domain considered semantically correct

Example: a low degree of semantic accuracy is when the name John

is stored as George. Both names are syntactically accurate, because

of the domain of reference in which they reside, but George is a

different name

Data Quality Model


Security

The capability of the data to be accessed and interpreted only by

authorized users Example: data that refer to personal or confidential information

like health or profit must be accessed only by authorized users or

must be written in secret code

Availability: The capability of data to be always retrievable Note: a particular case of availability is concurrent access (both

to read or to update data) by more than one user and/or

application Example: data must be accessible also during managing

operations like backup

Data Quality Model


Recoverability The capability of the data to maintain and preserve a specified

level of operations and its physical and logical integrity, even in

the event of failure This standard refers to the quality of data, not the system: the

characteristic of recoverability is related to the data that must be

recoverable

Note : Recoverability can be provided by features like commit /

synchpoint, rollback (fault-tolerance capability) or by backup-

recovery mechanisms Example: when a media device has a failure, data stored in that

device must be recoverable

Data Quality Model


Understandability

The extent to which the real meaning of data is easy for users to

comprehend

The extent to which data is in appropriate languages, symbols and

units, and

The degree to which data definitions are clear [5], [10]

Note : some information about data understandability are provided

by metadata

Example : To represent a State (within a country) , the standard

acronym is more understandable than a numeric code

Data Quality Model


Manageability

The capability of data to be stored appropriately from a functional

point of view Example : Data representing costs: stored like numeric and not

like string, to allow users to carry out algebraic operations Efficiency

The capability of data to be processed (accessed, acquired,

updated, etc) and to provide appropriate levels of performance

using the appropriate amounts and types of resources under

stated conditions Example : Using more space than necessary to store data can

cause waste of storage, memory and time

Data Quality Model


Changeability

The capability of data to be modified in its type, length or assigned

value for changes in technological environment, in requirements

or in functional specifications

Example : changing the “address” attribute in its length must be

allowed if needed

Portability: Also referred to as “Interoperability”

The capability of data to be moved from one platform to another;

this includes the capability of data to be also installed and

replaced in its destination platform. It refers particularly to

homogeneous and coherent set of data

Data Quality Model


Productivity

The capability of data to enable users to carry out his task in an

efficient way by using an appropriate amount of resources, and

the extent to which data is applicable and helpful for the task Data are productive for users when they satisfy the scope and the

goal of his information needs

Safety The extent to which data is related to their capability to achieve an

acceptable level of risk to people, businesses, properties or the

environment in a specified context of use

Example : data concerning blood group are relevant to users of

health care computer systems

Data Quality Model


Credibility The extent to which data are regarded as true and credible by

users Accessibility

The capability of data to be accessed, particularly by people who need supporting technology or special configuration because of some disability.

Example : data that must be managed by a screen reader cannot be stored as an image.

Regulatory compliance The capability of data to adhere to standards, conventions or

regulations in force and similar rules relating to data quality.

Data Quality Model


Questions & Answers

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