17 Database Design Using the REA Data Model（课件）- 《会计信息系统英文版》同步教学（人民大学版）

Chapter 17 Database Design Using the REA Data Model 17-1 Learning Objectives Discuss the steps for designing and implementing a database system. Use the REA data model to design an AIS database. Draw an REA diagram of an AIS database. Read an REA diagram and explain what it reveals about the business activities and policies of the organization being modeled. 17-2 Database Design Process 17-3 System Analysis Conceptual Design Physical Design Implementation & Conversion Operation & Maintenance The System Analysis Process Systems Analysis Initial planning to determine the need for and feasibility of developing a new system Judgments about the proposal’s technological and economic feasibility Identify user information needs Define the scope of the proposed new system Gather information about the expected number of users and transaction volumes to make preliminary decisions about hardware and software requirements Conceptual Design Developing the different schemas for the new system at the conceptual, external, and internal levels 17-4 The System Analysis Process (cont’d) Physical Design Translating the internal-level schema into the actual database structures that will be implemented in the new system New applications are developed Implementation and Conversion Includes all the activities associated with transferring data from existing systems to the new database AIS Testing the new system Training employees Maintaining the New System Data Modeling Process of defining an information system so it represents an organizations requirements Occurs at two stages of the design process: System analysis Conceptual design Data models: Data flow diagrams (Chapter 3) Flow charts (Chapter 3) Entity-relationship diagrams (Chapter 17) 17-6 Entity-Relationship Diagrams Used to graphically represent a database schema Depicts entities Anything an organization wants to collect information about Relationships between entities 17-7 E-R Diagram Variations 17-8 Resources-Events-Agents Diagra