In this KnowledgeKnugget™ you will learn a simple but effective method for balancing the levels of a dataflow diagram that automatically reveals overlooked data flows and sometimes even entire missing processes. Once you have exploded a process on your data flow diagram to a lower level of detail, you need to balance the two levels to ensure completeness and avoid missing pieces early in the project when it is still cheap to add them. Waiting until later in the process to discover them has proven to be a very expensive endeavor.

What Is the Business Value of Balancing a DFD and how do I do It?

Hello, I’m Tom Hathaway. I’m wearing my BA hat to symbolize that anyone in an organization might do business analysis, whether or not they have the job title “Business Analyst”, so let’s talk business analysis. This KnowledgeKnugget™ explains what it means to “balance” or “level” data flow diagrams, what the business value is, and how to do it in a very simple, efficient manner. This simple technique will help you when you are the one wearing the BA hat.

Given that you have created a Context Data Flow Diagram (Context DFD) and exploded one or more processes down to a lower level of detail, you are not really done yet. If you are going to rely on the diagram being accurate and complete, you would be well advised to balance the process on the Context Diagram with the lower level diagram. This simple step is one of the best reasons for creating and using DFDs to represent, present, and analyze how a process works. Level balancing will identify errors early in the project when it is still cheap to fix them. But what are you balancing and how does it work?

There are actually two steps to balancing the individual levels of DFDs. The first step is very simple in that you are comparing flows entering and leaving the detail level diagram with the higher level diagram. To do that, I need to be able to view the diagram containing the process I exploded and the lower-level data flow diagram at the same time.

To demonstrate the balancing process in real life, we are going to use a context-level diagram showing an ENTER ORDERS process and the lower-level diagram. We developed both diagrams working with Mary, the Department Manager of the Order Entry department, and Paul, an Order Entry Clerk that reports to Mary. In the event that you are not familiar with the situation these models depict, here are the original interview notes all decisions are based on.

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