The L2 Logical Scenario viewpoint of NAF v4 is a diagram type that allows you to model OperationalPerformers and the OperationalExchanges between them, which are encapsulated by the concept of a Needline.

The Needline concept is provided in System Architect’s NAF v4 (and underlying UAF domain meta model) support to be compliant with the domain metamodel of DoDAF 2.02, NAF 3.1, MODAF 1.2, and DNDAF 1.7. Since it is not specifically stated in the UAF DMM, the (NAFrx) suffix is added to the name – ‘r’ for relationship; ‘x’ for extension.

You may specify the OperationalExchange of each Needline within the Needline definition, by either drag-and-dropping OperationalExchanges from the Choices dialog, or clicking the + button to add an OperationalExchange. You may choose to display the OperationalExchange on each Needline by right-mouse clicking on the Needline and choosing Display options.

You may draw Needlines manually between OperationalPerformers on the diagram, or have System Architect automatically generate OperationalExchanges and Needlines by running utilities on the Tools > NAF 4 Utilities menu. Running autogeneration of Needlines produces a report of what Needline was created, what OperationalExchange(s) caused it to be created, and what Needlines were found that were manually created.

You may drag-and-drop Performers from the Explorer tree onto the Operational Structure diagram; auto-generated and manually-created Needlines are automatically drawn.