Purchasing Managers' Index, PMI is a composite indicator. This indicator is obtained through surveys on purchasing managers of interviewed enterprise every month and compiling survey results. Purchasing managers usually refer to the most senior person in a company in charge of raw material payments or product purchase amounts. As far as the manufacturing sector is concerned, managers or supervisors of higher ranks from procurement related departments (procurement, capital and material, supply chain management, etc.) usually fill out questionnaires. In some cases, high-rank staff from finance related departments answer questionnaires. As for non-manufacturing sectors, due the lack of the physical stock concept, procumbent managers are hard to intuitively define. Therefore, high-rank supervisors from merchandise planning departments, public affairs departments, investment departments, or financial departments may be ones filling out questionnaires.
Taiwan Purchasing Managers' Index, PMI is in reference to the compilation method of U.S. Institute for Supply Management, ISM. The survey scope covers manufacturing and non-manufacturing sectors. Among them, the diffusion index of manufacturing is compiled using five items: new orders, production, employment, inventories, and supplier deliveries. Components of non-manufacturing include four diffusion indexes: business activity, new orders, employment, supplier deliveries.
The Purchasing Managers' Index, PMI is between 0%~100%. If higher than 50%, it means manufacturing or non-manufacturing is in the expansion phase. If lower than 50%, it means it is in the contraction phase.