Operational Excellence is the state in which stable, improving operations are the norm — where deviations become visible and are handled systematically by the organisation itself, without depending on individuals or external consultants.
Where Lean is a collection of principles and methods, Operational Excellence describes the result: an operation that runs stably, discovers its own problems and improves itself. It requires three layers: visibility (metrics and boards), routines (Daily Management) and behaviour (management that responds to deviations rather than firefighting).
The test is simple: does the operation still run when the key person is on holiday? If the answer is no, the operation is carried by people — not by systems.