tailieunhanh - Lecture Software requirements engineering - Lecture­ 2

After this chapter the student should have acquired the following knowledge and skills: Introduction to course, what is a requirement? types of requirement, what is requirement engineering process? system engineering and software requirements, system engineering, software requirement engineering, software requirements document, sample requirements document. | Lecture-2 Recap 2 Introduction to course What is a requirement? Types of requirement What is requirement engineering process? System engineering and software requirements Today’s Lecture Software Requirements Engineering 3 System engineering Software requirement engineering Software requirements document Sample requirements document Why system engineering? 4 There is a close relationship between software and more general system requirements General system requirements Software requirements Systems engineering Computer-based systems fall into two broad categories: User-configured systems where a purchaser puts together a system from existing software products Custom systems where a customer produces a set of requirements for hardware/software system and a contractor develops and delivers that system 5 Classes of custom systems Information systems Primarily concerned with processing information which is held in some database. Embedded systems Systems where software is used as a . | Lecture-2 Recap 2 Introduction to course What is a requirement? Types of requirement What is requirement engineering process? System engineering and software requirements Today’s Lecture Software Requirements Engineering 3 System engineering Software requirement engineering Software requirements document Sample requirements document Why system engineering? 4 There is a close relationship between software and more general system requirements General system requirements Software requirements Systems engineering Computer-based systems fall into two broad categories: User-configured systems where a purchaser puts together a system from existing software products Custom systems where a customer produces a set of requirements for hardware/software system and a contractor develops and delivers that system 5 Classes of custom systems Information systems Primarily concerned with processing information which is held in some database. Embedded systems Systems where software is used as a controller in some broader hardware system Command and control systems Essentially, a combination of information systems and embedded systems where special purpose computers provide information which is collected and stored and used to make decisions 6 Emergent properties Emergent properties are properties of the system as a whole and only emerge once all of its individual sub-systems have been integrated Examples of emergent properties Reliability Maintainability Performance Usability Security Safety 7 The systems engineering process 8 System engineering activities System requirements engineering The requirements for the system as a whole are established and written to be understandable to all stakeholders Architectural design The system is decomposed into sub-systems Requirements partitioning Requirements are allocated to these sub-systems Software requirements engineering More detailed system requirements are derived for the system software 9 System engineering activities Sub-system .