You can create NSV-4 data flow diagrams to view the flow of data among system functions. You can also create functional decomposition diagrams to view system functions in a hierarchical structure.
The NSV-4 Functional Decomposition diagram can be used as an alternative or in conjunction with the NSV-4 Data Flow diagram. This diagram is similar to a node tree or functional hierarchy diagram.
1 Click File > New Diagram.
2 In the Select New Type for All Methods dialog box, double-click one of the following diagram types:
NSV-4 Data Flow
Describes the flow of data among system functions, and the relationships between systems or system functions and activities at nodes
NSV-4 Functional Decomposition
Describes system functions in a hierarchical structure
3 In the New Diagram dialog box, type a name for the diagram; then click OK.
4 Draw the diagram.
The following symbols and relationships are used on the Systems Functionality Data Flow diagram:
System Function
Indicates a step in the flow of data
External
Represents an object that sends information or data to the system, or takes information from the system, but is not itself part of the system
System Data Exchange Line
Indicates the direction of the flow of data as it moves from one point in the system to another
Data Store
The location where data rests when it is neither flowing nor being operated on; a data store can be a database, hard disk or a file on a disk
5 To drag previously defined system functions into the diagram, right-click an empty space in the diagram; then click Choices.