Purchasing Managers' Indexes (PMI) are economic indicators derived from monthly surveys of private sector companies. Institute for Supply Management (ISM) is the oldest, and the largest, supply management association in the world. Founded in 1915, the U.S.-based not-for-profit educational association serves professionals and organizations with a keen interest in supply management, providing them education, training, qualifications, publications, information, and research. ISM releases its PMI composite index (formerly known as the Purchasing Managers’ Index) on the first business day of each month.