PM-CMP-0020

Importing a model MUST NOT change it. All coupling MUST be recorded in the importing model.

Non-normative, and it is the assertion the whole composition story depends on. Together with PM-FLT-0070 it means an Object model verified alone stays valid once imported, so conformance tests compose and impact analysis is tractable.

The blog's figures demonstrate it directly. Comparing IMG:filter-and-operations-separated-models with IMG:filter-and-operations-united-in-the-entry-managhement, every cell the Component contributes is drawn in red and no black cell differs between the two. Composition is additive, cell by cell, in the source's own artefact.