The term "controls system disinvolvement" refers to the process of disengaging or disconnecting a controls system. Synonyms for this phrase include deactivation, shut down, disconnection, and isolation. Deactivation is the act of turning off or stopping a system from functioning. Shutting down refers to the process of closing or ending the operation of a system. Disconnection involves separating one system from another. Isolation is the act of setting apart or detaching one system from others. These are just a few options for expressing this concept, and each synonym can be useful in different contexts depending on the specific situation.