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Data Flow Diagrams. Documenting the Flow of Information within a System. A Data flow diagram (DFDs) describes the flow of data within an information system, while ignoring the equipment used to store it. Symbols. A Process. 1. A rectangular box with curved corners. Get Video Details.
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Documenting the Flow of Information within a System • A Data flow diagram (DFDs) describes the flow of data within an information system, while ignoring the equipment used to store it.
Symbols • A Process 1 A rectangular box with curved corners. Get Video Details It represents an action that does something with data.
Symbols • An Entity Member A Square Box Represents a person, department or organization that is outside the system but interacts with the system. An entity is either a source (where data comes from) or destination (where data goes)
Symbols • A Data Store A Narrow rectangular box with one end opened D1 Video File Represents anything that stores data
Symbols • A Data Flow An Arrow Video Number The Arrow Head indicates the direction of the flow
Scenario • Describe the activities that a cashier in the video store would perform when you rent a video.
Processes • Get Video Number • Get Video Details • Get Member Number • Get Member Details • Compute Bill Total • Get payment • Print receipt
Entities • Cashier • Video • Member