Rather than dive straight into reviewing new software, you start by mapping out the current logical data flow. Let’s say your HR department has an outdated approach and system for tracking job applicants. It’s the “how” fueling the “what.” The physical DFD then provides the basis of an implementation plan to provide the new software, hardware, people or other physical pieces needed to run the business process. In this sense, the physical DFD becomes the method of giving the business what it needs. This becomes the basis for the new physical DFD, depicting that physical implementation of devices, software, files and people to enable the business processes. This new logical DFD models what data flows are necessary to create the better functioning, no matter what the technical solution or how the system will be implemented.Īfter the new logical DFD is drawn, it in turn can be used to figure out the best method to implement the business activities in an upgraded system. Then, with a solid understanding of the current business activities, you can model a better way with a new state logical DFD, showing new features and functioning based on what the business analysis has revealed. Doing logical models reduces the risk of missing business requirements that otherwise would arise belatedly in the process, causing delays and rework. The discipline of mapping out the current logical flow will help everyone involved to gain a deeper understanding and reveal mistaken assumptions, misunderstandings or shortcomings. They will serve as a bridge from business needs to technical requirements. They will serve as a good tool for collaborating and communicating about better information and functioning, without concern for the “how” yet. They will likely make sense to the people working in the business activities. Depending on its scope, the current logical DFD may take time to produce and seem tedious, but the time may be well spent.Īnother benefit of logical DFDs is that they tend to be more easily understandable to non-technical people.

As with any diagram, the logical DFD should be detailed enough to be actionable. Or, you may already know the type of functionality you’re seeking to add, and the current logical DFD will help to reveal process steps that may need to be dropped or changed. By starting with a current logical DFD, you map the flow of business actions as they exist, which can highlight any shortcomings or inefficiencies.

Physical vs logical ufed reader