OEE definition, OEE myths and OEE helpful hints
Total Overall Equipment Effectiveness or OEE is most often represented as a percentage. And in theory, if your production process (at least at the machine level) is running without problems (so to speak) then you should be able to obtain 100 percent OEE.
This total OEE percentage is created by multiplying (the percent of Availability time) x (the percent of Performance) x (the percent of Quality). Availability is the percentage of time the asset (machine) is up and running verses when it is down during planned production time. Performance is a measure of how effectively the assets are running compared to its expected rate of speed; while quality is the percentage of good compared with the total produced (which includes scrap) per the job / batch / order quantity expected to be produced.
Example: If the asset is available 90% of the time during a production run and if during that run the rate is 90% of the expected rate of speed for that part/asset combination and the Quality is 90% good pieces /parts produced out of the total produced…then the OEE is .90 x .90 x.90 = 72%.
But it’s not all about percentages. It’s about finding some measurement that helps you improve your production process. So, don’t let these myths lead to mistakes when implementing OEE…
All you really need is a dashboard…This is False!
- Dashboards are great for availability and downtime alerts but do little to explain or eliminate poor performance.
- Capturing other production related information may be the key to improving your factory floor.
- Make sure you know the part and operator associated with the equipment.
- When downtime or scrap occurrences are recorded, capture a reason code.
- This information can be used in a historical analysis (not a real-time dashboard) to gain insight into process changes that will in turn deliver actionable insights to improve efficiency.
You need direct machine monitoring for OEE to work…This is also False!
The underlying data needed for OEE can be captured simply with the right paperless manufacturing software that has an easy-to-use intuitive shop production tracking system. This newer style OEE tracker software package with touch screen operator interface is a quick way to obtain OEE related process improvement data without the additional expense of wiring up the machines.
Myth # 3…
OEE and SCADA projects are the same…Don’t’ believe it!
SCADA or Supervisory Control and Data Acquisition systems which add computerized process logic to your machines COULD be an important additional project.
However, it should be considered separate and not necessary for a successful OEE project. When included, SCADA can seriously raise costs and scope when the underlying need for just OEE can be addressed for much less cost with a MES software “package” implementation without “integration” services to build-out the operator/machine interfaces.
An HMI is the best approach to provide an interface for the operators…not really!
HMI or Human Machine Interface is designed to be a computer screen that can start equipment programs and control the machine. it’s a costly mistake to build an HMI if all you really need to obtain is OEE data. Why over spend on a HMI, when you can save money by doing this with a low cost, easy-to-install package approach instead of a custom HMI.
OEE HELPFUL HINTS…
- OEE projects too often get off track due to misunderstanding.
- Keep things moving forward and implement a quick, meaningful and actionable system.
- Read our whitepaper “ OEE Myths and Mistakes ” and discover how Factivity provides manufacturing intelligence that drives performance.
- Take a look now at this short 3-minute OEE Video and see for yourself OEE Video YouTube.