Requirements Engineering: What is RE? UFCE4S-10-3 Lecture One Stewart Green

2nd October 2007 Requirements Engineering UFCE4S-10-3 Lecture One2 Lecture Structure Motivation Systems Engineering Software Engineering Requirements Engineering

2nd October 2007 Requirements Engineering UFCE4S-10-3 Lecture One3 References Requirements Engineering, Sommerville, I., and Kotonya, G., John Wiley,1997 An Introduction to Requirements Engineering, Bray, I., Addison Wesley, 2002 Requirements Engineering, Macaulay, L.,Springer, 1996 System Requirements Engineering, Loucopoulos, P., and Karakostas, V., McGraw- Hill,1995

2nd October 2007 Requirements Engineering UFCE4S-10-3 Lecture One4 Motivation Late delivery Over budget Faulty products Wrong product Cost of fixing bugs

2nd October 2007 Requirements Engineering UFCE4S-10-3 Lecture One5 Software Intensive Systems Engineering

2nd October 2007 Requirements Engineering UFCE4S-10-3 Lecture One6 Software Engineering

2nd October 2007 Requirements Engineering UFCE4S-10-3 Lecture One7 Requirements Engineering

2nd October 2007 Requirements Engineering UFCE4S-10-3 Lecture One8 Requirements Elicitation Techniques Interviews Questionnaires Examination of documentation Standards Systems manuals Statement of requirements Prototyping Contextual Design Ethnographic approaches Conversation and interaction analysis

2nd October 2007 Requirements Engineering UFCE4S-10-3 Lecture One9 Problems Inconsistency Lack of clarity Ambiguity Redundancy Incompleteness Inaccuracy

2nd October 2007 Requirements Engineering UFCE4S-10-3 Lecture One10 Notations Natural language text Dataflow diagrams Entity-relationship diagrams Object and class diagrams Conceptual graphs (Sowa) Logics Prolog Formal specification languages, e.g. Z and CSP

2nd October 2007 Requirements Engineering UFCE4S-10-3 Lecture One11 Desirable Properties in Notations Facilitate communication Define system boundary Ability to express: Partitions Abstractions Projections Focus on problem, not solution Easily modifiable