Overall equipment effectiveness (OEE) is a Lean term you will often see associated with TPM and is considered a manufacturing best practice. OEE drives action within total productive maintenance and is a tool used to assess a facility's productivity by assigning it a numerical value.
The Father of TPM can actually be credited with the development of OEE. Seiichi Nakajima first introduced the concept of OEE in the early 1980s in a book published by the Japan Institute of Plant Maintenance. Nakajima was unsatisfied with the traditional models used to calculate efficiency and he set out to develop OEE, a model that would not be so easy to manipulate.
OEE has become a best practice tool because every possible loss in the production process is accounted for in one simple formula:
OEE = Availability x Performance x Quality
Don’t know your OEE Score?
The OEE calculator helps you determine Availability, Productivity, and Quality.
The production variables in the equation represent TPM's Six Big Losses. You will need to plug in these different measurements to get each variable for the equation. As an example, we will look at availability rate, which is calculated from available time divided by the scheduled operating time. In the OEE equation, the availability rate can be impacted by unplanned stops (equipment failing or breaking down) and planned stops (the operator's scheduled lunch break).
Are OEE & TPM the same?
The terms OEE and TPM are not interchangeable, but rather OEE is a powerful tool used in TPM. The percentages and numbers you use to calculate OEE may seem complicated, but it does give you a good representation as to how efficiently your facility is running. OEE can be best used to measure the performance and reliability of a particular piece of equipment and identify where it may be experiencing losses. As you go through your facility's Lean journey, it will be important to continue calculating the OEE, so you can keep track of progress and judge whether or not solutions implemented were beneficial.
