Requirements Engineering Requirements Engineering:

Transcript:Requirements Engineering Requirements Engineering::
Requirements Engineering Requirements Engineering: User and system requirements, Functional and non-functional requirements, Types & Metrics, A spiral view of the requirements engineering process. Software Requirements Specification (SRS): The software requirements Specification document, The structure of SRS, Ways of writing a SRS, structured & tabular SRS for an insulin pump case study Requirements elicitation & Analysis: Process, Requirements validation, Requirements management. Case Studies: The information system. Case study – Mental health care patient management system (MHC-PMS). RE is a process of - establishing the services - that the customer requires from a system - & - the constraints, under which it operates & is developed. RE is a process of - identifying - what customer requires from a system & - how it can be fulfilled, - with available resources - (manpower, time, cost, hardware and software resources etc.) Requirement can range from - a high level abstract statement - of a service or of a system constraint - to - a detailed mathematical functional specification. Types of Requirements User requirements – - collection of statements in natural language - description of services, that system provides. - written for customers. System requirements – - structured document, of detailed requirements - & services provides by the system. - contract between client & contractor. Software specification – - detailed software description. - that can serve as a basis for design or implementation. - written for software developers. Requirements Engineering Tasks Inception Elicitation Elaboration Negotiation Specification Validation Requirements Management 1. Inception Specifying the beginning of the software project - (for what purpose the software is required?) Stakeholders – - do rough feasibility study & - identify scope of the project. The purpose of inception is to - - Establish the basic understanding of the project - Find out all possible solutions - Establish – effective communication between developer & customer. 2. Elicitation Requirement Discovery Sometimes - It is difficult to understand the customer needs, because – Customer may not specify sufficient requirements or may specify too many requirements Sometimes – - customer find it difficult to communicate - with system engineer, about their needs. Customer may give – - ambiguous & confusing requirements – - intentionally or unintentionally 3. Elaboration Information about – Requirements – - is expanded & refined. Technical model of – - software functions, features & constraints - Is prepared. Modeling & refinement of requirements is done - user scenarios are