Information and Databases

4 Information and Databases

Table 4.1Using a CAD System to Design the Boeing 777

Table 4.1Using a CAD System to Design the Boeing 777 CUSTOMER Boeing’s manufacturing department Airline maintenance departments

Table 4.1Using a CAD System to Design the Boeing 777 PRODUCT Specification of the precise function, shape, and location of each component Verification that the components are physically compatible

Table 4.1Using a CAD System to Design the Boeing 777 • BUSINESS PROCESS • Major Steps: • Decide on major features of airplane • Design individual components • Test for compatibility with other components and other subsystems • Transmit the specifications to manufacturing • Rationale: • Use a paperless design process to avoid delays related to copying and moving paper, and to use the design data directly to test for interference between components.

Table 4.1Using a CAD System to Design the Boeing 777 PARTICIPANTS Representatives of airlines Boeing engineers INFORMATION General design goals CAD specification of the shape, location, materials, and function of each component TECHNOLOGY CAD database and computer for storing the data Terminals and data network

Figure 4.1Entity-relationship diagram for part of a university registration system

Figure 4.2Types of relationships in entity-relationship

Table 4.2Possible Attributes for the Entity Types in Figure 4.1 • DEPARTMENT • Department identifier • College • Department head • Scheduling coordinator • COURSE • Course number • Department • Required of department major (y/n) • Course description • SECTION • Section identification number • Semester • Year • Classroom • Start time • End time • Days of week for class meetings • PROFESSOR • Employee identification number • Name • Address • Birthdate • Office telephone • Social Security number • STUDENT • Student identification number • Name • Address • Birthdate • Telephone • Gender • Ethic group • Social Security number • OFFICE • Office number • Building • Telephone extension

Figure 4.3 Images produced by information systems

Table 4.3Excerpt from a Hypothetical Student File Social security number: 044-34-5542 Last name: Bates First name: Alvin Street address: 243 Third Street City: Middleton State: MA Zip code: 02137 Date of birth: 05/07/78

Figure 4.4 Entity-relationship diagram from a relational database

Figure 4.5Posing a query in Microsoft Access

Figure 4.6Using a natural language query

Figure 4.7A Multidimensional database

Figure 4.8Using a geographical information system

Figure 4.9Use of schemas and subschemas

Figure 4.10Locating data using direct access

Figure 4.11Locating data using indexes

Figure 4.12Backup and recovery

Figure 4.13Retrieving a Web page

Table 4.4Differences between Using a Relational Database and Using the World Wide Web BASIC STRUCTURAL ELEMENTS Traditional database: Tables, records, fields, keys The World Wide Web: Web pages and hyperlinks BASIC ORGANIZING PRINCIPLE Traditional database: Predefined tables and relationships that have a specific meaning in a specific business context The World Wide Web: Author-defined links from any location in a Web page to any other location on the same Web page or to another Web page FINDING SPECIFIC INFORMATION Traditional database: Identify specific records or fields in those records and the DBMS will find them The World Wide Web: Identify a specific Web address (URL) and the browser will find and display the page if it is available FINDING INFORMATION RELATED TO THE INFORMATION MOST RECENTLY ACCESSED Traditional database : No typical method The World Wide Web : Click on a hypertext link METHOD FOR IDENTIFYING DATA REQUIRED IN A QUERY Traditional database: State selection criteria in terms of specific values of specific data items in specific tables The World Wide Web: Identify words or terms that should appear in the Web pages selected by the search engine

Table 4.4Differences between Using a Relational Database and Using the World Wide Web HOW THE COMPUTER FINDS THE DATA BY SEARCHING Traditional database: DBMS finds the pertinent tables in the database and selects the appropriate data from the records that meet the criteria The World Wide Web: Search engine finds every Web page containing each word or phrase in the query, then prioritizes these based on the priorities in the query TREATMENT OF IMPOSSIBLE OR RIDICULOUS QUERIES Traditional database: DBMS rejects queries not phrased in terms of tables, fields, and relationships in the database The World Wide Web: The search engine performs whatever search is requested LIKELIHOOD THAT A QUERY WILL PRODUCE USABLE RESULTS Traditional database: DBMS returns exactly what is requested; if the user asks the wrong question, the result may not be useful The World Wide Web: Many of the Web pages found by a search engine may be unrelated to what the user wanted METHODS FOR CONTROLLING DATA QUALITY Traditional database: During data entry DBMS checks for obvious errors such as missing values, out-of-range values, etc. The World Wide Web: The Web has no organized method of controlling quality of information in Web pages

Table 4.5Determinants of Information Usefulness and Related Roles of Information Syatems • INFORMATION QUALITY • ACCURACY • PRECISION • COMPLETENESS • AGE • TIMELINESS • SOURCE

Table 4.5Determinants of Information Usefulness and Related Roles of Information Systems • INFORMATION ACCESSIBILITY • AVAILABILITY • ADMISSIBILITY • INFORMATION PRESENTATION • LEVEL OF SUMMARIZATION • FORMAT • INFORMATION SECURITY • ACCESS RESTRICTION • ENCRYPTION

Figure 4.16Do managers expect the truth?

Fig 4.17Diagram representing a mental model

Figure 4.18A virtual reality simulation

Information and Databases