Understanding Data Flow Diagrams (DFDs)

A Data Flow Diagram (DFD) is a graphical representation of the flow of data through an information system, modeling its processes. It shows how data enters and leaves the system, what processes transform the data, and where data is stored. DFDs are a fundamental tool in structured systems analysis and design.

Alternative Names for Data Flow Diagrams

Data Flow Diagrams are known by several names in the field of system analysis. One very common alternative name for a Data Flow Diagram is the bubble chart.

• The term "bubble chart" is often used because processes in a DFD are typically represented by circles or ovals, which look like bubbles.
• These "bubbles" represent the activities or functions that process data.
• Arrows connect these bubbles, showing the direction of data flow.

Comparing DFDs with Other Diagram Types

It's helpful to understand why the other options are not correct alternative names for a Data Flow Diagram:

• Flow chart: A flow chart typically shows the sequence of operations or the flow of control in a program or process, using different shapes for different actions (start/end, process, decision, input/output). While related, a flow chart focuses on control flow and step-by-step execution, whereas a DFD focuses on data movement and transformation.
• Di-graph: A directed graph (di-graph) is a mathematical concept representing a set of vertices connected by edges, where the edges have a direction. While a DFD can be considered a type of di-graph (vertices are processes/stores, edges are data flows), "di-graph" is a very general term and not a specific common name for a DFD in systems analysis.
• Pictorial graph: This is a very general term that could apply to many types of diagrams or charts that use pictures or symbols. It is not a specific name for a Data Flow Diagram.

Based on standard terminology in systems analysis and design, "Bubble chart" is a widely recognized alternative name for a Data Flow Diagram.

Conclusion on Data Flow Diagram Names

The question asks for another name for a Data Flow Diagram (DFD). Among the given options, "Bubble chart" is the recognized alternative name due to the common representation of processes as circles or 'bubbles'.

Revision Table: Data Flow Diagram Key Concepts

Additional Information: DFD Levels and Usage

DFDs can be drawn at different levels of detail:

• Context Diagram (Level 0 DFD): Shows the entire system as a single process ('bubble') interacting with external entities. It defines the system boundary.
• Level 1 DFD: Decomposes the main process into its major sub-processes, showing data flows between them and data stores.
• Further Levels (Level 2, etc.): Decompose processes from higher levels into even more detailed sub-processes.

DFDs are used in systems analysis to understand the current system (physical DFD) or to model a proposed new system (logical DFD). They help analysts and stakeholders visualize how data moves through a system, identifying bottlenecks or inefficiencies.