Requirements Engineering Requirements Elicitation Overview of Requirements Analysis

Agenda UML– practice, practice, practice,….. Preliminary Problem Analysis & Project Plan Requirements Elicitation & Analysis

Introduction to Requirements Its your worst nightmare. A customer walks into your office, sits down, looks you straight in the eye, and says, “I know you think you understand what I said, but what you don’t understand is what I said is not what I meant.” Invariably, this happens late in the project, after deadline commitments have been made, reputation are on the line, and serious money is on the stake.

Introduction to Requirements Definition “A feature of the system or a description of something the system is capable of doing in order to fulfill the system’s purpose” 4 Types of Requirements –Functional –Non-functional 4 Strengths –Must/Shall –Should –Will

Requirements Inception o How does a s/w project started? o Event based requirement or pertaining problem based requirement o Business need Elicitation o Problems of scope (the boundary of system) o Problems of understanding o Problems of volatility Elaboration Negotiation Specification o Written document with graphical models, formal mathematical models, scenarios, prototype, etc.

Requirements Engineering Problem analysis Problem description Prototyping and testing Documentation and validation Have we captured all the user need? Are we using the right techniques or views? Is this function feasible? Have we captured what the user expects? REQUIREMENTS ELICITATION AND ANALYSIS REQUIREMENTS DEFINITION AND SPECIFICATION

Software Requirement Specification Template ate.doc ate.doc

Requirements o Goal To understand the problem o Necessary to Understand Requirements Organization Existing Systems Processes Improvements o Once you have all this information, now what?

Establishing Groundwork Identifying stakeholders Recognizing multiple view points Working towards collaboration Asking the first questions o Who is behind this work? o Who will use the solution? o What will be the economic benefit of a successful solution? o Is there another source for the solution that you need?

Requirements Elicitation Techniques o Interview / Meeting o Survey / Questionnaire o Observation o Ethnography / Temporary Assignment o Business Plans o Review Internal / External Documents o Review Software

Information Gathering Organization Existing Systems Processes Improvements

Requirements Analysis o Goal To bridge the gap between the problem domain and the technical domain o Tasks Problem Recognition Evaluation and synthesis Modeling Specification Review

Requirements Analysis Principles o Information domain of a problem must be represented and understood o Models that depict system information, function, and behavior should be developed o Models must be partitioned in a manner that uncovers detail in a layered fashion o Analysis process should move from essential information toward implementation detail

Requirements Review? o Are the requirements complete? o Are the requirements concise? o Are the requirements correct? o Are the requirements consistent? o Are the requirements modular? Can they accommodate change? o Are the requirements realistic? o Is the requirement needed by the customer? o Are the requirements traceable?

Coming Up Next... Lecture: Requirements Analysis Methods