An Introduction to System Modeling
{"Image DocumentName": "An Introduction to System Modeling", "Image ImageDescription": "System Models. Data Flow Diagram. There are only three symbols and one connection: The rounded rectangles represent processes or work to be done. The squares represent external agents \u2013 the boundary of the system. The open-ended boxes represent data stores, sometimes called files or databases, and correspond to all instances of a single entity in a data model. The arrows represent data flows, or inputs and outputs, to and from the processes There are several competing symbol sets for DFDs. Most are named after their inventors (e.g., DeMarco/Yourdon, Gane/Sarson) or after a published standard (e.g., IDEF0, SSADM). Some analysts will argue semantics, but these data flow diagramming \u2018languages\u2019 generally support the same fundamental concepts and constructs. We have adopted the Gane and Sarson (Structured Analysis) notation because of its popularity and CASE tool support. Prepared by Kevin C. Dittman for. Systems Analysis & Design Methods 4ed. by J. L. Whitten & L. D. Bentley.", "Image XResolution": "37", "Image YResolution": "37", "Image ResolutionUnit": "Pixels/Centimeter", "Image Software": "SlidePlayer", "Image YCbCrPositioning": "Centered"}