2. References
• R.H. Thayer dan M. Dorfman, Software
Requirements Engineering, Second Edition, John
Wiley & Sons, 1999.
• Ian K. Bray, An Introduction to Requirements
Engineering, Addison Wesley, 2002.
• Karl E Wiegers, Software Requirements, Microsoft
Press, 2nd Edition, 2003.
• Ian Sommerville and Pete Sawyer, Requirements
Engineering: A Good Practice, Chichester England,:
John Wiley & Sons, 1997.
4. What is Requirements?
Requirements are a specification of what should be implemented.
(Sommerville and Sawyer, 1997)
A requirement is a singular documented need of what a particular
product or service should be or do. (Wikipedia, August 2009)
• Necessary Attributes/Properties,
Characteristics, Capabilities, Quality , and
Constraints
• In order to have value and utility to a user
5. What is Requirements Engineering?
• The process of establishing the services that the customer
requires from a system and the constraints under which it
operates and is developed (Ian Sommerville, Software
Engineering, 5th Edition, 1995)
• Investigating and describing the problem domain and
requirements and designing and documenting the
characteristics for a solution system that will meet those
requirements (Ian K. Bray, An Introduction to Requirements
Engineering, 2002)
• Set of activities concerned with identifying and
communicating the purpose of a software-intensive
system, and the contexts in which it will be used. (Steve
Eastbrook, Dept. Computer Science, Toronto University)
6. What is Requirements Engineering?
• Investigating and identifying
• Communicating and Documenting
8. Activities?
Feasibility Requirements
study elicitation and
analysis
Requirements
specification
Feasibility Requirements
report validation
System
models
U and system
ser
requirements
Requirements
document
9. What is Requirements Engineering?
• Investigating and identifying
• Communicating and Documenting
What requirements are not?
• Design and implementation details
• Project planning information
• Testing information
10. Why RE is Important?
120
Relative Cost to Correct a Defect
100
80
60
40
20
0
Requirements Design Code Test Operation
Development Phase
Source: Wiegers, 2003
Requirements are a specification of what should be implemented. (Sommerville and Sawyer, 1997). They are descriptions of how a system should behave, or of a system property or attribute. They may be a constraint on the development process of the system. a requirement is a singular documented need of what a particular product or service should be or do. It is most commonly used in a formal sense in systems engineering or software engineering . It is a statement that identifies a necessary attribute, capability, characteristic, or quality of a system in order for it to have value and utility to a user. [1] In the classical engineering approach, sets of requirements are used as inputs into the design stages of product development . Requirements show what elements and functions are necessary for the particular project.