Quality improvement: how does it differ from quality assurance?

Quality improvement? How does it differ from Quality assurance? The "Total Quality Management" movement which has been so successful in improving the quality of manufactured products in Japan and more recently in the United States has arrived in American service industries, including health care. Although a minority of health care institutions has adopted the Continuous Quality Improvement (CQI) or Total Quality Management (TQM) philosophy and techniques on their own, the new Joint Commission on Accreditation of Health Care Organizations (JCAHO) standards to be phased in over the next 3 years require all accredited hospitals to "adopt the new philosophy".