Download Software Engineering CS 501 Lecture 6: Requirements Analysis and Specification and more Slides Software Engineering in PDF only on Docsity! CS 501: Software Engineering Fall 2000 Lecture 6 (a) Requirements Analysis (continued) (b) Requirements Specification docsity.com Administration • Introduction of André Allavena • Due date for Assignment 1 is Wednesday 5 p.m. • Teaching Assistant assignment to projects will be made on Thursday docsity.com Requirements Analysis Methods for data modeling and design • Data flow diagrams • Entity-relation diagrams • Data dictionaries • Object models Many of these methods blur the distinction between analysis and design. docsity.com Entity-Relation Model A Design Methodology for Relational Databases • A database of entities and relations • Tools for displaying and manipulating entity- relation diagrams • Tools for manipulating the database (e.g., as input to database design) Warning: There is much confusion about definitions and notation docsity.com Entity-Relation Diagram An entity A relation between entities An entity or relation attribute An inheritance relation docsity.com MARC Format for Monographs (Books) 001 89-16879 r93 245 Campus strategies for libraries and electronic information 260 {Bedford, Mass.} : Digital Press, c1990. 650 Academic libraries--United States--Automation. 650 Libraries and electronic publishing--United States. 700 Arms, Caroline R. (Caroline Ruth) docsity.com Entity-Relation Diagram for MARC Book Short title Catalog record Describes Control numb Subject heading Is about Creator Editor of Author of 1:n 1 0:n 0:n 0:n 0:n 0:n 0:n docsity.com Data Dictionaries A data dictionary is a list of names used by the system • Brief definition (e.g., what is "date") • What is it (e.g., number, relation) • Where is it used (e.g., source, used by, etc.) • May be combined with a glossary As the system is implemented, the data dictionary in the requirements is input to the system data dictionary, which is a formal part of the system specification. docsity.com Examples of Non-Functional Requirements Privacy (Mercury digital library) Functional requirement: Usage data for management of system Non-functional requirement: Usage data must not identify individuals Minimizing records (NeXT) Functional requirement: Retain all required records Non-functional requirement: Discard all other records docsity.com Unspoken Requirements
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Requirements Specification What is the purpose of the Requirements Specification? docsity.com Requirements Specification: Purpose 3. It records the requirements for the future • An essential part of system evolution 4. If may be a contractual document • See you in court! docsity.com Requirements Specification: Approaches • Natural language • Structured natural language • Design description language • Requirements specification language • Graphical notation • Formal specification See Sommerville, Chapter 7. docsity.com
