Effectiveness and efficiency of care of the critically ill patient are subject to a number of systemic influences, including skills of individual physicians/nurses (technical and non-technical), team-working in the intensive care unit (ICU), and the ICU environment. We first discuss the paper of Fackler and colleagues as a contribution to the systems approach to clinical performance in the context of intensive care. We then highlight features of care delivery that are unique to intensive care and discuss the need for better understanding of human and non-human elements of the system of care of the critically ill patient as a driver for improvement of care delivery.