L8 – Logical Constraints

A L8 Logical Constraints View specifies operational or business rules, which may be behavioural, or may simply be non-functional constraints, on the way that business is done in the Enterprise.

Concerns Addressed

• User Requirements Specification (Non-Functional).
• Operational Constraints.

Background

The L8 View is used to constrain the logical architecture without forcing a particular solution. L8 is used for rules which are not expressed as behavioural models, interactions or measures of effectiveness, i.e. they are textual statements of requirement that constrain the architecture.

Usage

• Definition of business rules.
• Identification of operational constraints.

Representation

• Structured Text.
• UML diagram with associated UML constrain

Detailed View Description

At the mission level, the L8 View may be based on business rules, such as those contained in doctrine, guidance, rules of engagement, etc. At lower levels, L8 describes the rules or constraints under which the architecture or its nodes behave under specified conditions. Such rules can be expressed in a textual form, for example:

“If (these conditions) exist, and (this event) occurs, then (perform these actions).”

These rules are contrasted with the business or doctrinal standards themselves, which provide authoritative references and provenance for the rules (see A8, Standards).

The rules captured in a L8 View are logical, specified independently of any given solution, whereas constraints that are specific to resources are defined in P8, Resource Constraints. L8 rules can include such guidance as the conditions under which operational control passes from one entity to another or the conditions under which a human role is authorised to proceed with a specific activity.

Figure 3-413: Example L8 View

Operational constraints may act upon nodes, operational activities, Logical Data Models, Entities and Security Domains. Consequently, L8 constraints may be associated with L4, Logical Activities, and it is often useful to overlay the rules on a L4 view.

Key Elements and Their Relationships

Meta-Model

The detailed meta-model and element list for L8, Logical Constraints, is at paragraph 4.4.8.