This exercise asked you to answer two questions relating to a portion of a sample data flow diagram, illustrated below:
You entered:
Sample data flow diagram consisting of 1) Vendor 2) Order 3) Clerk
Data Flow Answers
Following are the questions and the correct answers. (Your answers may vary slightly.)
What do the parallel lines located between the Vendor and Clerk squares represent? The parallel lines between the Vendor and Clerk squares represent a database.
How would you interpret in a single sentence and in the proper order, how data is being handled in the diagram?
A single sentence that describes the order of data handling in the diagram would read like this:
A clerk places an order with a vendor and then records that order in the database.
The data flow diagram (DFD) provided represents the flow of data between various components of a food management or cafeteria management system. Below is an analysis of its key components:
External Entities:
Administrative Assistant: Updates the daily rate and requests perishable items.
Vendors: Supplies both perishable and non-perishable items.
Processes (Data Processing Units):
Invoicing System (Process 1):
Handles student invoicing.
Updates daily rates.
Manages payments and generates itemized invoices at the end of the month.
Sends and receives data from the "Stores Issues and Control System."
Stores Issues and Control System (Process 2):
Manages inventory, including tracking low stock and items issued.
Coordinates vendor supplies and orders non-perishables.
Exchanges data with the invoicing system.
Perishable Ordering (Process 3):
Manages the ordering and requisition of perishable goods.
Works closely with vendors supplying perishables.
Data Stores:
Invoices: Stores invoices for student billing.
Expenses: Stores extra data related to expenses.
Vendor: Stores vendor-related details.
Stores Inventory: Stores stock data for inventory management.
Orders: Stores order-related information.
Vendor (Perishable): Tracks perishable vendors.
Orders (Perishable): Stores perishable order details.
Data Flow:
The diagram shows how data moves between entities, processes, and data stores.
Payments, invoices, orders, and stock updates are key data flows.
Vendor supplies move into inventory, and orders are placed for replenishment.
Summary:
This DFD represents a structured process of handling student invoicing, inventory management, and vendor ordering in a food or cafeteria system. It efficiently tracks financial transactions, inventory usage, and procurement processes.
Invoicing System dataflow diagram
Data Flow Diagram (DFD) Description
A data flow diagram (DFD) is a graphical representation of the flow of data within a system, illustrating how inputs are transformed into outputs through various processes. It is a crucial tool for analysts seeking to understand and optimize the information handling within an organization. Here is how an analyst should interpret a DFD:
Identify Components: A DFD is composed of four primary components:
entities,
processes,
data stores, and
data flows.
Entities are external actors that interact with the system, processes transform inputs into outputs, data stores represent places where data is held, and data flows depict the movement of information. Analysts must first identify these components to understand the overall structure of the system.
Understand Data Flow: Examine how data moves between entities, processes, and data stores. Follow the arrows that represent data flows, ensuring a clear understanding of the origin, transformation, and destination of each piece of information. This will help in identifying any inefficiencies or bottlenecks in the data handling process.
Analyze Processes: Focus on the processes within the DFD. Each process should have a clear input and output, and the analyst should understand how input data is transformed into output data. If a process is complex, it may need to be decomposed into a lower-level DFD for more detailed analysis.
Examine Data Stores: Look at how data is stored and retrieved within the system. Analyze whether data is stored redundantly, if there are any potential data integrity issues, and whether data retrieval is efficient. Ensure that data stores are adequately represented and linked to the processes that use them.
Evaluate External Entities: Consider the entities that interact with the system. Ensure that all necessary interactions are represented and that the data exchanged is accurate and complete. Analyze whether any external dependencies could pose risks to the system’s operation.
Check for Consistency and Completeness: Ensure that the DFD is consistent and complete. Every data flow should originate from and terminate at a valid component, and all data processes should be linked to data input and output. Validate that the DFD accurately represents the real-world system it is modeling.
Identify Opportunities for Improvement: Use the insights gained from the analysis to identify opportunities for optimizing data flows and processes. Look for ways to simplify complex processes, eliminate redundant data stores, and streamline data flows to enhance efficiency and reduce potential errors.
Validate with Stakeholders: Once the analysis is complete, validate the findings and recommendations with stakeholders to ensure that the DFD accurately represents their understanding of the system and that the proposed changes align with organizational objectives and constraints.
Document Findings and Recommendations: Clearly document the findings from the DFD analysis, including any identified issues and recommended improvements. This documentation will serve as a valuable resource for implementing changes and for future analyses.
In summary, interpreting a data flow diagram requires a meticulous examination of the components, data flows, and processes within a system. By systematically analyzing each aspect of the DFD, an analyst can gain valuable insights into how data is handled, identify potential areas for improvement, and contribute to the optimization of the organization’s information handling processes.
