September 19, 2021
Fab Flowers’ fleet of 500 vehicles delivers gifts and flowers to customers in seven states. Several steps occur for this complicated ordering and delivery system to work smoothly. A data flow diagram (DFD) is a visual flow chart that defines the data flows, processes, and stores involved in managing a multi-state operational process (What, n.d.). The DFD for Fab Flowers’ system is a physical diagram showing how the system will work (Logical vs. Physical, n.d.). The context and level 0 diagrams provided here tell the visual story of a customer placing an order with Fab Flowers.
List of Sources/Sinks, Data Flows, Stores, and Processes
Before designing a DFD, it is important to create a list of crucial elements that make up the diagram. The four primary elements of a DFD include external entities (sources/sinks), data flows, stores, and processes (Sharma, 2015; Valacich & George, 2020; What, n.d.). Each element is defined by a symbol representing how information flows through and around the ordering and delivery system. The diagrams below use a slightly modified version developed by Gane and Sarson (Valacich & George, 2020, pg. 182). The modification is that processes and stores do not have a highlighted section for the numbers due to the limitations of the design program.
The following list of external entities, processes, flows, and stores were adapted from Figures 7-3, 7-4, and 7-5 in Modern Systems Analysis and Design by Valacich & George (2020, pgs. 183-185). The items listed under each element can be found in Figures 1 and 2 below. These two structured analyses tools will help the team check for completeness, make inferences from user cases, and find missing requirements (Sharma, 2015). The list serves as written documentation of items in the diagrams, along with their Gane and Sarson symbols. Figures 1 and 2 tell the visual story of data flow in the Fab Flowers ordering and delivery system.
External Entities (Rectangles)
There are five external entities included in the ordering and delivery system DFD. The customer places the order and gets a receipt. The fulfillment center receives the product order, packages and ships the products, recording the shipping data for drivers and updates to the goods sold and inventory files. The system sends the payment to the bank, and managers can view and analyze daily sales and inventory data reports. External entities define the borders of the system, and in this diagram include:
- Fulfillment center
Data Flows (Arrows)
Data flows are data in motion, moving together from one part of the system to another (Valacich & George, 2020). These flows are critical to the seamless flow of data and operations in the ordering and delivery system. There are duplicate flows for “delivery data” and “payment data” because the same information is going to two separate locations. Further, there is a “shipment data” flow and a “shipping data” flow. Shipment data includes all data as it relates to packaging and shipping products. Shipping data is specific information the driver will need to deliver products. The ordering and delivery system data flows include:
- Customer order
- Product order
- Shipment data
- Payment data
- Deposit data
- Credit data
- Goods sold
- Formatted goods sold
- Daily goods sold amounts
- Inventory data
- Formatted inventory data
- Daily inventory depletion amounts
- Shipping data
- Delivery data
- Formatted delivery data
- Daily delivery data
- Management reports
Processes (Rectangle with Rounded Corners)
The eight processes below are verb-focused elements that change the data flowing in from an external entity, store, or another process to produce an output (What, n.d.). The single process in the context diagram is the system itself—the order and delivery system. The context diagram was kept simple and concise, with just the main elements at play in the system (Valacich & George, 2020). The level 0 DFD includes processes 1.0-8.0. Each performs a specific action on the data flowing in or out of it. Processes include:
0. Order and delivery system
1.0. Receive and transform customer order
2.0. Record payment
3.0. Make bank deposit
4.0. Update customer master
5.0. Update goods sold file
6.0. Update inventory file
7.0. Ship products
8.0. Produce management reports
Data Stores (Long Rectangle, Right Side Missing)
Data needs to sit somewhere without being transformed or manipulated; these are called data stores (Valacich & George, 2020). The stores of information in the Fab Flowers system DFD are those connecting payment and distribution operations to the whole system. The inventory file will update both shipment and delivery data for specific reporting structures. The three data stores include:
- Customer master file
- Goods sold file
- Inventory file
Context Diagram for Fab Flowers Ordering & Delivery System
Note: Some elements of the context diagram were adapted from Figure 7-4 in Valacich & George’s (2020, pg. 184) book, Modern Systems Analysis and Design.
Level 0 Diagram for Fab Flowers Ordering & Delivery System
Note: Some elements of the level 0 diagram were adapted from Figure 7-5 in Valacich & George’s (2020, pg. 185) book, Modern Systems Analysis and Design.
Further System Development Considerations
Topics to discuss with the development team include those surrounding security and the organization of state-by-state data. Specifically, the program’s dynamic design should allow regional managers to view just their state’s data while allowing upper management to view all, sort, and manipulate data. These data flow diagrams can help the project team develop use cases and draw inferences, critical to developing the organized data flows in the final system (Sharma, 2015). Sufficient time should be spent on use-case testing to ensure the program works efficiently and effectively.
The context and level 0 diagrams tell the visual story for Fab Flowers’ ordering and delivery system that supports 500 vehicles in seven states. The DFD focuses on how data is transformed, complete with inputs, outputs, and conversions of that data (Sharma, 2015). Customers place an order, which is sent to the fulfillment center, and payment is processed. The fulfillment center packages and ships the products, updates the appropriate stores, and sends delivery data to the drivers. Managers can then retrieve reporting data on daily goods sold, inventory depletion, and delivery completions.
Logical vs. Physical Data Flow Diagram. (n.d.). Lucidchart. Retrieved on September 18, 2021, from https://www.lucidchart.com/pages/data-flow-diagram/logical-vs-physical-data-flow-diagram
Sharma, A. (2015, April 28). Data flow diagrams – are they worth it? BA Times. https://www.batimes.com/articles/data-flow-diagrams-are-they-worth-it/
Valacich, J. S., & George, J. F. (2020). Modern systems analysis and design (9th ed.). Pearson Education, Inc.
What is a Data Flow Diagram? (n.d.). Lucidchart. Retrieved on September 17, 2021, from https://www.lucidchart.com/pages/data-flow-diagram#section_0