Requirements engineering as a structured process: Requirements Engineering Requirements Engineering Field Why are Requirements so important? Requirements Engineering Activities Requirements Elements Requirements Quality Requirements quality indicators Conclusion

1. Prepared by :
Dr. Hamdan M. Al-Sabri

2. Outline
2Prepared by: Dr.Hamdan M. Al-SabriRequirments Engineering
Requirements Engineering
Requirements Engineering Field
Why are Requirements so important?
Requirements Engineering Activities
Requirements Elements
Requirements Quality
Requirements quality indicators
Conclusion

3. Requirements Engineering [1,2]
3Prepared by: Dr.Hamdan M. Al-SabriRequirments Engineering
 What is requirement?
 A documented representation of a condition or capability
 Requirements Engineering
 The science and discipline concerned with analyzing and
documenting requirements
 Functional or non-functional
 Requirements Engineer
 Social skills ,
 Technical skills

4. Purpose of Requirements Engineering [3]
4Prepared by: Dr.Hamdan M. Al-SabriRequirments Engineering
 Determine the requirements for a system.
Functional
Non-functional
 Support consequent development activities
Architecture design,
 Implementation, and
 Test.

5. Requirements Engineering Filed
5Prepared by: Dr.Hamdan M. Al-SabriRequirments Engineering

6. Why are Requirements so important? [4]
6Prepared by: Dr.Hamdan M. Al-SabriRequirments Engineering

7. Why are Requirements so important? [4]…
7Prepared by: Dr.Hamdan M. Al-SabriRequirments Engineering

8. The Inputs and Outputs for RE [2]
8Prepared by: Dr.Hamdan M. Al-SabriRequirments Engineering

9. Requirements Engineering Activities [5]
9Prepared by: Dr.Hamdan M. Al-SabriRequirments Engineering
Requirements Engineering
Requirements Development Requirements Management
Traceability Change ManagementR Elicitation R Analysis R Specification R Validation

10. Requirements Elements
10Prepared by: Dr.Hamdan M. Al-SabriRequirments Engineering
 Human Part
Stakeholders are those who pay for the system
Users are represented interacts with system to achieve
required work;
Developers are the team who design and maintain the
system.
Requirement Engineer
Technical Part
Techniques, methods, tools, approach

11. A Good Set of Requirements is…
 Correct
 Unambiguous
 Complete
 Consistent
 Verifiable
11Prepared by: Dr.Hamdan M. Al-SabriRequirments Engineering

12. Requirements quality indicators [4]
Requirments Engineering 12Prepared by: Dr.Hamdan M. Al-Sabri

13. Requirements quality indicators [4]..
 Imperatives
 command words, indicating something that is of absolute necessity.
(Shall, Must, Is required to, Are applicable, Should)
 good indicator
 Directives
 words are often used to make requirements more
understandable.(e.g., For example, Figure, Table ,Note)
 good indicator
13Prepared by: Dr.Hamdan M. Al-SabriRequirments Engineering

14. Requirements quality indicators..
 Continuances
 are words or phrases that follow imperative words and phrases in a
requirement statement, and introduce more detailed specification.
 (below, as follows, following, listed, in particular, support, and )
 good indicator
 Options
 loosen the specification by allowing the developer latitude in
implementing a requirement. This introduces risks to schedule and
cost.
 (can, may, optionally)
 not good indicator
14Prepared by: Dr.Hamdan M. Al-SabriRequirments Engineering

15. Requirements quality indicators..
 Weak phrases
 include words and phrases that introduce uncertainty into
requirements statements. .(not good indicator)
 ( adequate , as appropriate, as preferred, as possible)
 not good indicator
 Size
• includes counts of three indicators:
• total lines of text
• total number of imperative phases
• total number specification statements
15Prepared by: Dr.Hamdan M. Al-SabriRequirments Engineering

16. Conclusion
 Requirements Engineering (RE) is the science and
discipline concerned with analyzing and
documenting requirements
 Requirements Engineering is a subfield from
software engineering.
 Some requirements quality indicators according to
IEEE803
 Imperatives, Directives , Continuances , Options
and Size
Requirments Engineering 16Prepared by: Dr.Hamdan M. Al-Sabri

17. References
[1] Hendrik Meth , Manuel Brhel, Alexander Maedche " The state of the art in
automated requirements elicitation", Information and Software Technology
55 (2013) 1695–1709, Elsevier 2013.
[2] Tore Dybå, Daniela S. Cruzes," Process Research in Requirements
Elicitation", 978-1-4799-1011-3/13 , 2013 IEEE.
[3] http://www.sse.uni-due.de/en/research-focus/requirements-engineering.
[4] Nathan Carlson · Phil Laplante, “The NASA automated requirements
measurement tool: a reconstruction”, © Springer-Verlag London 2013.
[5] Hamdan Al-Sabri, Ahmed Emam,” A Development-Oriented Requirements
Engineering (DORE) Approach for Improving Requirements Development”,
ACEAIT,2014, Japan.
Requirments Engineering 17Prepared by: Dr.Hamdan M. Al-Sabri

18. Thanks, Questions
Requirments Engineering 18Prepared by: Dr.Hamdan M. Al-Sabri