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Software Development Center
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 4
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
Software Quality Requirements & Evaluation 5
Agenda
Targets Of Quality Models 3
Structure Used For The Quality Models2
Product Quality Model 4
Quality In Use Model 5
Data Quality Model 6
Organization Of SQuaRE Series Of International Standards
1
Software Quality Requirements & Evaluation 6
Organization Of SQuaRE Series Of International Standards
Figure 1 — Organization of SQuaRE series of International Standards
Software Quality Requirements & Evaluation 7
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
Software Quality Requirements & Evaluation 8
Organization Of SQuaRE Series Of International Standards
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.
Software Quality Requirements & Evaluation 9
ISO/IEC 2504n - ISO/IEC 2504n -
Quality Evaluation Quality Evaluation
DivisionDivision
Organization Of SQuaRE Series Of International Standards
● Provide requirements, recommendations and
guidelines for software product evaluation, whether
performed by evaluators, acquirers or developers
Software Quality Requirements & Evaluation 10
Agenda
Organization Of SQuaRE Series Of International Standards
1
Structure Used For The Quality Models2
Targets Of Quality Models 3
Product Quality Model 4
Quality In Use Model 5
Data Quality Model 6
Software Quality Requirements & Evaluation 12
Agenda
Organization Of SQuaRE Series Of International Standards
1
Structure Used For The Quality Models2
Product Quality Model 4
Quality In Use Model 5
Data Quality Model 6
Targets Of Quality Models 3
Software Quality Requirements & Evaluation 14
Agenda
Organization Of SQuaRE Series Of International Standards
1
Targets Of Quality Models 3
Structure Used For The Quality Models2
Quality In Use Model 5
Data Quality Model 6
Product Quality Model 4
Software Quality Requirements & Evaluation 16
Product Quality Model
Product quality model What It Means
Functional 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
Software Quality Requirements & Evaluation 17
Product Quality Model
Product quality model What It Means
Compatibility
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
Software Quality Requirements & Evaluation 18
Product Quality Model
Product quality model What It Means
Usability
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
Software Quality Requirements & Evaluation 19
Product Quality Model
Product quality model What It Means
Reliability
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
Software Quality Requirements & Evaluation 20
Product Quality Model
Product quality model What It Means
Security
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
Software Quality Requirements & Evaluation 21
Product Quality Model
Product quality model What It Means
Maintainability
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
Software Quality Requirements & Evaluation 22
Product Quality Model
Product quality model What It Means
Portability
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
Software Quality Requirements & Evaluation 23
Agenda
Organization Of SQuaRE Series Of International Standards
1
Targets Of Quality Models 3
Structure Used For The Quality Models2
Product Quality Model 4
Data Quality Model 6
Quality In Use Model 5
Software Quality Requirements & Evaluation 25
Quality In Use Model
Quality in use model What It Means
Effectiveness 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
Software Quality Requirements & Evaluation 26
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
Quality In Use Model
Software Quality Requirements & Evaluation 27
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
Software Quality Requirements & Evaluation 29
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
Software Quality Requirements & Evaluation 30
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
Software Quality Requirements & Evaluation 31
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
Software Quality Requirements & Evaluation 32
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
Software Quality Requirements & Evaluation 33
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
Software Quality Requirements & Evaluation 34
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
Software Quality Requirements & Evaluation 35
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
Software Quality Requirements & Evaluation 36
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
Software Quality Requirements & Evaluation 37
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
Software Quality Requirements & Evaluation 38
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
Software Quality Requirements & Evaluation 39
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
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