L1 – Node Types

The L1 Node Types View specifies the types of logical Node used in the architecture. The nodes can be organised into a specialisation hierarchy (subtype-supertype).

Concerns Addressed

• User Requirements.
• Operational Planning.
• High-Level Systems Requirements.

Background

The L1 View defines all of the Nodes that will appear in a Logical Architecture. Nodes are elements of capability that are assembled and orchestrated in the Logical Architecture (see L2, Logical Scenario, and L4, Logical Activities, views). The levels of capability provided by each node are expressed as Measures of Performance (MoPs), and these may be dependent on the environments in which the Node is required to operate.

Nodes are traced to the Capabilities they manifest using the Capability For Node relationship. MoPs may be specified for each node that maps to the MoE of the Capabilities. Each Measure can be expressed in terms of the environment – e.g. higher performance may be expected in clear weather than in bad.

Usage

• Initial set up of a Logical Architecture.
• Defining MoP for requirements specification purposes.
• Defining the types of environment in which Nodes may operate.

Representation

• Topological (connected shapes).
• Tabular.

Detailed View Description

The L1 view can either be shown as a diagram that traces nodes to capabilities (also showing required MoP), as shown in Figure 3-26, or as a table as shown in Figure 3-27:

Fig 3-26

Fig 3-27

The L1 View helps to de-clutter the L2, Logical Scenario View by taking care of the properties and capabilities mappings that were previously shown in NAF v3.1 in NOV-2. It is still possible to show capabilities and properties in the L2 View if required though.

Key Elements and Their Relationships

Figure

Meta-Model

The detailed meta-model and element list for L1, Node Types, is at paragraph 4.4.1.