CSC 426 Chapter 09, Fall 2011

Chapter 9 UML for Database Application Design 1 Objectives When fact-finding techniques are used in the database system development lifecycle. The types of facts collected throughout the database system development lifecycle. The types of documentation produced throughout the database system development lifecycle. The most commonly used fact-finding techniques. How to use each fact-finding technique and the advantages and disadvantages of each. 2 Objectives About a Web-based DVD rental company called StayHome Online Rentals. How to use fact-finding techniques in the database planning, systems definition, and requirements collection and analysis stages of the database system development lifecycle. Examples of the types of documentation created in the database planning, systems definition, and requirements collection and analysis stages of the database system development lifecycle. 3 Fact-finding The formal process of using techniques such as interviews and questionnaires to collect facts about systems, requirements, and preferences. Many occasions for fact-finding during the database system development lifecycle. Particularly crucial to the early stages of the lifecycle, including the database planning, system definition, and requirements collection and analysis stages. 4 What facts are collected and when? 5 Fact-finding techniques A database developer normally uses several fact-finding techniques during a single database project, including: Examining documentation, Interviewing, Observing the business in operation, Research, Questionnaires. 6 Examining documentation Examining documents, forms, reports, and files associated with the current system, is a good way to quickly gain some understanding of the system. 7 Examples of documentation to examine 8 Advantages / disadvantages of examining documentation 9 Interviewing Interviewing is the most commonly used, and normally most useful, fact-finding technique. Objectives include: finding out and/or checking facts; generating user interest and/or feelings of involvement; identifying requirements and/or gathering ideas and opinions. 10 Advantages / disadvantages of interviewing 11 Interviewing Management activities that allow stages of database system development lifecycle to be realized as efficiently and effectively as possible.  Should be integrated with overall IS strategy of the organization. Includes creation of the mission statement and mission objectives for the database system. 12 Interviewing There are two types of interviews: unstructured and structured. Unstructured interviews are conducted with only a general objective in mind and with few, if any, specific questions. In structured interviews, the interviewer has a specific set of questions to ask the interviewee. 13 Interviewing There are two types of questions: open- ended and closed. Open-ended questions allow the interviewee to respond in any way that seems appropriate. Closed-ended questions restrict answers to either specific choices or short, direct responses. 14 Observing the business in operation One of the most effective techniques. Can either participate in, or watch a person perform activities to learn about the system. 15 Advantages / disadvantages of observation 16 Research Useful to research the application and problem. Computer trade journals, reference books, and the Internet are good sources of information. May find how others have solved similar problems, plus you can learn whether or not software packages exist to solve your problem. 17 Advantages / disadvantages of research 18 Questionnaires Can conduct surveys through questionnaires. Questionnaires are special-purpose documents that allow you to gather facts from a large number of people while maintaining some control over their responses. 19 Questionnaires There are two formats for questionnaires: free-format and fixed-format. Free-format questionnaires offer the respondent greater freedom in providing answers. Fixed-format questionnaires contain questions that require specific responses from individuals. 20 Advantages / disadvantages of questionnaires 21 The StayHome case study This case study describes aon online DVD rental company called StayHome, which rents out DVDs to its members. The first warehouse and head offices of StayHome was established in 1982 in Seattle but the company has now grown and has three additional warehouses in different states of the United States. 22 Home page for the StayHome Online Rentals Web site 23 Web page of member of staff called Sally Adams 24 Web page (1) for new member of StayHome Online Rentals 25 Web page (2) for new member of StayHome Online Rentals 26 Web page for browsing DVDs available at StayHome Online Rentals 27 An example of the DVDs that Ann Peters wishes to view 28 StayHome case study – database planning (mission statement) 29 StayHome case study – database planning (mission objectives) 30 StayHome case study – system definition (system Boundary) 31 StayHome case study – system definition (user views) 32 Cross-reference of user views with the main types of data 33 Use case diagram for the Member user view 34 Use case diagram for the Assistant user view 35 Use case diagram for the Manager user view 36