Constraint Extraction Guide

Purpose

Constraints are obligations that must hold for the procedure to be valid.

Constraints are not primitive names.

Constraints should be phrased as testable statements.

Guidance

• State what must be true before a step can occur.
• State what must be true for the procedure to continue.
• State what must be true for the procedure to terminate.
• Distinguish required conditions from optional interpretive detail.

Examples

• Evidence cannot be evaluated before it exists.
• A decision requires either sufficient confidence or a justified stopping condition.
• A loop requires a condition that determines whether to continue or stop.
• A classification framework may not require action.
• A coordination framework may require communication before coordinated action.