tailieunhanh - Lecture Accounting information systems: Basic concepts and current issues (4/e): Chapter 7 - Robert L. Hurt

Chapter 7 - Data flow diagramming. When you've finished studying this chapter, and completing the activities at its conclusion, you should be able to: Explain the symbols and design considerations associated with DFDs; compare and contrast flowcharts and DFDs with regard to purpose, content, structure, and use in accounting information systems; discuss the ways in which DFDs are used in AIS work; construct a leveled set of DFDs; design normalized database tables from a DFD. | Chapter 7 Data Flow Diagramming Outline Learning objectives Nature and purpose of DFDs DFD symbols Leveling and balancing Database design Normal forms Learning objectives Explain the symbols and design considerations associated with DFDs. Compare and contrast flowcharts and DFDs with regard to purpose, content, structure, and use in accounting information systems. Discuss ways DFDs are used in AIS work. Construct a leveled set of DFDs. Design normalized database tables from a DFD. Nature and purpose of DFDs Not as widely used as flowcharts in accounting practice Two main purposes Understanding a business process Understanding the relational database that underlies the AIS Focus on data DFD symbols process external entity data flow data store DFD symbols customer order Take customer order customer order database Leveling and balancing Data flow diagrams are prepared in leveled sets. Each level reveals more detail than the one before it. Levels must be balanced, which means that external entities and data flows at the boundary cannot “disappear” between levels. Leveling and balancing Level names Context diagram Level Zero diagram Level One diagrams Level Two diagrams And so on. . . Leveling and balancing Context diagram Highest level view of the system Exactly one in a leveled set Exactly one process One or more external entities No data stores Customer 0 Order taking process Customer order Invoice Leveling and balancing Level Zero diagram Exactly one in a leveled set More detail than the context diagram Preserve data flows at the boundary Customer Customer order Invoice Process customer order. Bill customer. Processed customer order Leveling and balancing Level One diagram May be more than one in a leveled set More detail than the Level Zero diagram Each Level One focused on a single “bubble” from Level Zero Preserve data flows at the boundary See the example on the next slide, which “explodes” Process (Process customer order) from the Level Zero . | Chapter 7 Data Flow Diagramming Outline Learning objectives Nature and purpose of DFDs DFD symbols Leveling and balancing Database design Normal forms Learning objectives Explain the symbols and design considerations associated with DFDs. Compare and contrast flowcharts and DFDs with regard to purpose, content, structure, and use in accounting information systems. Discuss ways DFDs are used in AIS work. Construct a leveled set of DFDs. Design normalized database tables from a DFD. Nature and purpose of DFDs Not as widely used as flowcharts in accounting practice Two main purposes Understanding a business process Understanding the relational database that underlies the AIS Focus on data DFD symbols process external entity data flow data store DFD symbols customer order Take customer order customer order database Leveling and balancing Data flow diagrams are prepared in leveled sets. Each level reveals more detail than the one before it. Levels must be balanced, which means that .