Video Transcript Excerpt
Creating a Low Level Data Flow Diagram to Analyze Business Processes
Data Flow Diagrams (DFDs) are a tool for visualizing, presenting, analyzing, and discussing business activities. They demonstrate how processes and sub-processes of an organization use, transform, transport, and store business data. At the context level, a DFD is a picture of the scope of your project. To truly understand the inner workings of processes that are in scope for your project, you need to expose the internal processes, data flows, and data stores. We will demonstrate how to create a lower level diagram based on a context level DFD, interview notes from Mary, the department manager of the Order Entry Department (our project sponsor), and the internal processes described therein.
In an earlier KnowledgeKnugget™, we showed you a technique for identifying potential processes that will be visible on a lower level DFD. Applying this technique (or any other you come up with yourself), you should be able to recognize the following potential internal processes from the interview notes:
SORT MAIL VERIFY CREDIT VALIDATE ITEMS GROUP VALID ORDERS
To create a lower-level diagram, we need access to Paul, an Order Entry clerk who reports to Mary. He is actively involved in the process we are exploding and helped us interpret the interview notes to identify the internal processes.
Looking at the Context diagram, the "Orders, Complaints, and Payments" data flow from the CUSTOMER is where it all starts. Based on the interview notes and our list of potential internal processes, SORT MAIL appears to be the first step in the process.
The customer triggers all the action in our department. We receive an order (with or without payment), a complaint, or a payment (with or without invoice copy) from the customer. These are separated and the following actions take place:
Therefore, I start my detailed diagram on the left side of a new sheet of paper with the Orders, Complaints, and Payments flow coming from the left into the process SORT MAIL.
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