Flujo de datos en el diseño arquitectónico
Data Flow in Architectural Design
Understanding Data Flow Diagrams (DFD)
- A Data Flow Diagram (DFD) is a graphical tool that illustrates the paths data takes within a computer program, allowing for visualization of data movement.
- DFDs help identify data storage and define how data is transported through system inputs and outputs.
Components of a Data Flow Diagram
- Key components of a DFD include geometric shapes: ovals represent the start or end of processes, diamonds indicate decisions, and rectangles denote actions or activities.
- DFDs consist of external entities (sources outside the system), internal entities (within the system), and processes that manage data flow.
External Entities
- External entities are information sources not part of the system, such as other businesses or individuals that interact with it. Examples include clients and sensors.
- These external sources provide unmodifiable data to the system, which must be utilized by software engineers without alteration.
Internal Entities
- Internal entities are components within the system itself, where developers can manipulate data. This includes personnel contributing information to the design process.
Processes in DFD
- Processes in a DFD illustrate how input data transforms into output information. For instance, receiving an email file requires understanding its physical path through various stages.
Constructing a Data Flow Diagram
Steps to Create a DFD
- Identify Scope: Determine what activities will be observed within the software's boundaries.
- Define Activities: Specify project activities that will be converted into software functions; for example, students needing bus schedule information.
- Create Diagram: Develop the actual DFD representing how requests for information are made and responses received.
Example Application Development
- In designing an app for students to access public transport info, steps include defining scope (routes/timings), naming relevant activities (requesting arrival times), and illustrating these interactions in a diagram.
Best Practices for DFD Construction
- Use infinitive verbs to describe activities clearly within your diagram; this enhances clarity regarding how data travels between entities via documents or information processed by the system.
- Represent data flow visually with lines indicating directionality; arrows show input/output relationships while side notes clarify content descriptions involved in each step.
Conclusion on Data Flow Representation
Data Flow Diagram Mapping
Key Principles of Data Flow Diagrams
- A data flow diagram (DFD) should be easy to explain and identifiable in its basic components, allowing for both hand-drawn and computer-generated representations.
- Recommendations for mapping a DFD include identifying external entities to define system boundaries and using meaningful names for processes and data flows.
- It is advised to use accessible vocabulary, avoiding technical jargon when possible. The focus should be on the process rather than the individuals performing it.
- The DFD must be easy to read, avoiding complexity; diagrams should be comprehensible, digestible, and visually appealing.
- All elements within the DFD must have clear relationships; processes need specified inputs and outputs, with data stores only relating to processes.
Balancing Processes in DFD
- Each process detailed in the DFD must be balanced, meaning that every lower-level process should correspond with an upper-level process regarding input and output data.
- Selecting a starting level is crucial; the DFD should specify where data tracking begins along with entry and exit points at each process level.
- Each high-level process can potentially evolve into its own DFD.