ITM 410 Chapter Notes - Chapter 4: Data Flow Diagram, Business Process, Flowchart

• School: Ryerson University
• Department: Information Technology Management
• Course: ITM 410
• Professor: Selcuk Savas

Document Summary

There are two types of system documentation: data flow diagram and system flowcharts. Data flow diagram: data flow diagram: is a graphical representation of a system it shows the system components, data flows, sources, destinations and storage of data. Clerks (person), department (place), computer (thing: it specifies where, how and who and it didn"t tell us what activities are being accomplished. Logical data flow diagram pg 107: logical data flow diagram: is a graphical representation of the system showing the system"s process, data stores, and the flows of data into and out of the processes and data stores. It looks at what the system is performing and not where, how and who. It looks at the activities that a system performs. The diagram is also known as level 0 diagram. When both dfds have the same external entities, it is known as balanced. The successive subdividing or exploding of logical dfds are called top-down partitioning.