Data Flow Diagrams can be understood by both technical or nontechnical person because they are very easy to understand.It is used as the part of system documentation file.Data Flow Diagram represent detailed and well explained diagram of system components.It is a graphical representation which is very easy to understand as it helps visualize contents.It helps us to understand the functioning and the limits of a system.Levels of DFDĭFD uses hierarchy to maintain transparency thus multilevel DFD’s can be created. A single DFD can have maximum processes upto 9 and minimum 3 processes.The DFD should maintain consistency across all the DFD levels.
The processes should be numbered or put in ordered list to be referred easily.The name of the entity should be easy and understandable without any extra assistance(like comments).Modeled systems also communicate with terminator. It can be, for example, organizations like banks, groups of people like customers or different departments of the same organization, which is not a part of the model system and is an external entity. The Terminator is an external entity that stands outside of the system and communicates with the system. When the data flow from the warehouse it is considered as data reading and when data flows to the warehouse it is called data entry or data updation. The data warehouse can be viewed independent of its implementation. The warehouse is simply not restricted to being a data file rather it can be anything like a folder with documents, an optical disc, a filing cabinet. Two horizontal lines represent the symbol of the store. The data is stored in the warehouse for later use. The direction of flow is represented by the arrow which can also be bi-directional. A given flow should only transfer a single type of information. Material shifts are modeled in systems that are not merely informative. Data flow also represents material along with information that is being moved.
A relatable name should be given to the flow to determine the information which is being moved. The arrow symbol is the symbol of data flow. The process is named a short sentence, in one word or a phrase to express its essenceĭata flow describes the information transferring between different parts of the systems. The symbols of a process are rectangular with rounded corners, oval, rectangle or a circle. Input to output transformation in a system takes place because of process function.