Overall input efficiency and total equipment efficiency

For years, overall equipment effectiveness (OEE) has been considered the ultimate efficiency index for production equipment, especially in the semiconductor industry where the equipment costs constitute some two-thirds to three-quarters of the total production costs. This paper asserts that the OEE is only half of the full efficiency equation. The concept of overall input equipment efficiency (OIE) is proposed to complete the full equation of the equipment efficiency. The multiplication of the OIE and OEE thus constitutes the true overall equipment efficiency which the author names total equipment efficiency (TEE) in order not to confuse with the current OEE. The importance of OIE with respect to OEE is explained. The differences between the well-known cost of ownership and the OIE/TEE are also explained.