SYSE.Preface:2 - One System can appear in several engineering structures

An engineered System can be the project focus, a part of a using or containing System, the bearer of functions, the result of realization Work, one configuration in a product family, a participant in operation, and the subject of evidence. Each position expresses a different relation. Each pattern states that relation and the decision for which it matters. Ownership does not prove parthood; interaction does not prove membership; a description is not the described System; a release record is not the released configuration; and a passed component test does not establish an outside benefit.

Describe the operational environment through the containing, using, neighbouring, and interacting Systems and the conditions that matter to the current use. Call a System a suprasystem only when the engineered System under discussion is its proper part. SYSE.16 restores those relations; SYSE.17 follows the planned use, realization, operation, maintenance, misuse, and change to Systems that can bear benefit, harm, or another engineering consequence.