The administrative machinery for planning, delivering and monitoring health care provided by health professionals and their supporting staff. This may range from running a small primary-care centre to organising a large hospital, or being responsible for meeting the health needs of a region or a nation. Whether the overall structure for providing care is state-funded, insurance-based, private-practice or a mixture of these, health service management is essential in an era of rapidly evolving and expensive scientific medicine. Health service managers are administrators with special training and skills in managing health care; sometimes they are doctors, nurses or other health professionals, but many have been trained in management in commercial, civil service or industrial environments.