Data Flow Diagrams (DFD) Overview

This collection of flashcards covers key terminology and concepts related to Data Flow Diagrams, their construction, and application.

Data Flow Diagram (DFD)

A graphical representation of the flow of data within a system.

Data Flow

Represents the movement of data between processes, data stores, and entities.

Process

Transforms input data flows into output data flows, described by verbs.

Data Store

Inventories of data, which can take the form of files, tables, etc.

Entity

A person, place, or thing that provides or receives data in the system.

Decomposition Diagram

A diagram that outlines processes of a system in a hierarchical manner.

Context Diagram

Illustrates the internal and external entities and data flows to and from the root node.

Level 0 Data Flow Diagram

A diagram using main processes of the root node from the Decomposition Diagram.

Level 1 Data Flow Diagram

A detailed diagram representing subprocesses from the Level 0 diagram.

DFD Symbols

Rectangles, circles, and arrows used to represent data inputs, outputs, and storage.

Top-Down Approach

A method of developing DFDs starting from the highest level down to specific details.

Data Store Rules

A data store must connect to at least one process in a DFD.

External Entities

Sources or destinations that are not part of the system but interact with it.

Do's and Don'ts of DFDs

Guidelines to ensure the proper flow of data in DFDs, avoiding incorrect connections.

Grocery List

An example of a data flow in the context of preparing ingredients for an action.

Physician's Office Billing System

A specific case study demonstrating the application of DFD concepts.