Information concerning Needlines and the OV-2 Nodes they relate is maintained in the repository. You can generate Needlines by using the Information Exchange Generation utility.

The following image shows an example of a node connectivity diagram.

You can manually draw Needlines between nodes on an OV-2 diagram, using the Needline draw tool from the Draw toolbar. You can also automatically create Needline definitions in the repository by running the Generate Information Exchange Definitions utility.

Needlines are identified by their 'to' and 'from' operational nodes. The Source & Destination tab of a Needline definition contains values for its From Operational Node and its To Operational Node. Both are read-only properties.

If the Needline has been generated automatically by the Generate Information Exchange Definitions utility, then the Maintained by Generation property is enabled, and read only. Needlines that you draw manually have the Maintained by Generation property cleared.

When you open an OV-2 diagram, it is checked for both of the following conditions:

Any lines that meet these requirements are deleted from the diagram automatically. You can run the Draw Needlines command to redraw lines on the diagram.

For lines that you have manually drawn, the Maintained by Generation property is set to false and the diagram open logic ignores those lines, leaving them on the diagram.

In the Source & Destination tab of a Needline definition, you can click Edit IERs to open the Needline Navigator. The Needline Navigator highlights the sending and receiving nodes of the Needline selected, in the case below UAV and UAV Control.

The Information Exchange of the Needline is listed in the Information Exchange list at the bottom of the dialog, in this case Requested Target Data.

You can double‑click an Information Exchange to open its definition.

Starting with DoDAF 1.5, architects are encouraged to build Net Centric architectures, and establish capabilities and services provided and used by the architecture.

Within an Operational Node definition, you can specify if the Node is a Service Provider, Service Consumer, or Unanticipated User of Services. These three Operational Node definitions are prepopulated into every encyclopedia. You might conceivably create new Operational Node instances; however the DoDAF specification specifically calls out to categorize Nodes by one or more of these three roles.