This document discusses non-functional requirements in software engineering. It defines non-functional requirements as constraints on qualities like timing, performance, reliability that relate to the system as a whole rather than individual functions. These requirements are critical and failure to meet them can make a system unusable. The document outlines different types of non-functional requirements including product requirements, organizational requirements, and external requirements. It also notes challenges in specifying non-functional requirements precisely and potential conflicts between different stakeholder needs.
The waterfall model is a sequential (non-iterative) design process, used in software development processes, in which progress is seen as flowing steadily downwards (like a waterfall) through the phases of conception, initiation, analysis, design, construction, testing, production/implementation and maintenance.
The waterfall model is a sequential (non-iterative) design process, used in software development processes, in which progress is seen as flowing steadily downwards (like a waterfall) through the phases of conception, initiation, analysis, design, construction, testing, production/implementation and maintenance.
Requirements analysis, also called requirements engineering, is the process of determining user expectations for a new or modified product. These features, called requirements, must be quantifiable, relevant and detailed. In software engineering, such requirements are often called functional specifications.
Learn about Agile Methodology of Software Engineering and study concepts like What is Agile, Why Agile is there, Agile Principles, Agile Manifesto with Pros & Cons of it.
Presentation also include Agile Testing Methodology like Scrum, Crystal Methodologies, DSDM, Feature Driven Development, Lean Software Development & Extreme Programming.
If you watch this one please rate it and do share this presentation to others so then can easily learn more about the Agile Methodology.
Software Requirement Specification is a most important topic asked in exams and for presentations in B.Tech comp. engg. This presentation contains all the important topic and deep knowledge of SRS.It includes definition, scope, role, how to write srs, template and template description. It tells how to build SRS and also includes examples for ease.
This PPT throws light on some of the essential elements of the Agile methodology which has become crucial to ensure quality in this day and age. To know more on agile methodology, Scrum Model, Agile Principles and Scrum Board go through this presentation as well as the ones coming soon.
In software engineering, software configuration management (SCM or S/W CM) is the task of tracking and controlling changes in the software, part of the larger cross-disciplinary field of configuration management. SCM practices include revision control and the establishment of baselines.
This Presentation explains the SCM Process.
Requirements analysis, also called requirements engineering, is the process of determining user expectations for a new or modified product. These features, called requirements, must be quantifiable, relevant and detailed. In software engineering, such requirements are often called functional specifications.
Learn about Agile Methodology of Software Engineering and study concepts like What is Agile, Why Agile is there, Agile Principles, Agile Manifesto with Pros & Cons of it.
Presentation also include Agile Testing Methodology like Scrum, Crystal Methodologies, DSDM, Feature Driven Development, Lean Software Development & Extreme Programming.
If you watch this one please rate it and do share this presentation to others so then can easily learn more about the Agile Methodology.
Software Requirement Specification is a most important topic asked in exams and for presentations in B.Tech comp. engg. This presentation contains all the important topic and deep knowledge of SRS.It includes definition, scope, role, how to write srs, template and template description. It tells how to build SRS and also includes examples for ease.
This PPT throws light on some of the essential elements of the Agile methodology which has become crucial to ensure quality in this day and age. To know more on agile methodology, Scrum Model, Agile Principles and Scrum Board go through this presentation as well as the ones coming soon.
In software engineering, software configuration management (SCM or S/W CM) is the task of tracking and controlling changes in the software, part of the larger cross-disciplinary field of configuration management. SCM practices include revision control and the establishment of baselines.
This Presentation explains the SCM Process.
4. 4
Non-Functional Requirements - 1
• Most non-functional requirements relate to
the system as a whole. They include
constraints on timing, performance, reliability,
security, maintainability, accuracy, the
development process, standards, etc.
5. 5
Non-Functional Requirements - 2
• They are often more critical than individual
functional requirements
• Capture the emergent behavior of the system,
that is they relate to system as a whole
6. 6
Non-Functional Requirements - 3
• Must be built into the framework of the
software product
• Failure to meet a non-functional system
requirement may make the whole system
unusable
7. 7
Non-Functional Requirements - 4
• For example, if an aircraft system does not
meet reliability requirements, it will not be
certified as ‘safe’
• If a real-time control system fails to meet its
performance requirements, the control
functions will not operate correctly
8. 8
Non-Functional Requirements - 5
• Non-functional requirements arise through
user needs, because of budget constraints,
because of organizational policies, because of
the need of interoperability with other
software and hardware systems, or because of
external factors such as safety regulations,
privacy legislation, etc.
11. 11
Product Requirements Examples
• The system shall allow one hundred thousand
hits per minute on the website
• The system shall not have down time of more
than one second for continuous execution of
one thousand hours
13. 13
Organizational Requirements Examples
• The system development process and
deliverable documents shall conform to the
MIL-STD-2167A
• Any development work sub-contracted by the
development organization shall be carried out
in accordance with Capability Maturity Model
15. 15
External Requirements Examples
• The system shall not disclose any personal
information about members of the library
system to other members except system
administrators
• The system shall comply with the local and
national laws regarding the use of software
tools
16. 16
Observations on Non-Functional
Requirements - 1
• Non-functional requirements can be written
to reflect general goals for the system.
Examples include:
– Ease of use
– Recovery from failure
– Rapid user response
17. 17
Observations on Non-Functional
Requirements - 2
• Goals are open to misinterpretation
• Objective verification is difficult
• Distinction between functional and non-
functional is not always very clear
18. 18
Observations on Non-Functional
Requirements - 3
• Non-functional requirements should be
written in a quantitative manner as much as
possible, which is not always easy for
customers
• For some goals, there are no quantitative
measures, e.g., maintainability
20. 20
Observations on Non-Functional
Requirements - 5
• Chances of conflicts within non-functional
requirements are fairly high, because
information is coming from different
stakeholders. For example, different
stakeholders can give different response times
or failure tolerance levels, etc.
22. 22
Observations on Non-Functional
Requirements - 7
• Non-functional requirements should be
highlighted in the requirements document, so
that they can be used to build the architecture
of the software product
23. 23
Summary
• Discussed different aspects of the non-
functional requirements
• Non-functional requirements capture very
important emergent behavior of the
automated system
• Due importance, time, and resources should
be given to non-functional requirements
24. 24
References
• ‘Requirements Engineering: Processes and
Techniques’ by G. Kotonya and I. Sommerville,
John Wiley & Sons, 1998
• Software Requirements: Objects, Functions,
and States by A. Davis, PH, 1993
• Software Engineering 6th Edition, by I.
Sommerville, 2000
• Software Engineering 5th Edition, by R.
Pressman
