34. Process Capacity – OEE Intro
Overall Equipment Efficiency (OEE) is one of the commonly heard terminology within manufacturing industry, mostly due to the frequent usage for OEE to determine the efficiency and capacity of production equipment’s utilization. The introduction section will be mostly covering the definition of OEE and how general industry analyze and breakdown the elements and factors in equipment.
In General, OEE are consists of three common factors around the industry.
- Availability
- Performance
- Quality
These three factors can be calculated based on the following fractions before accumulating the OEE%
OEE Calculation for Each Critical Component
But in general, the availability, performance and quality concepts could be vague if the details are not illustrated or classified. Therefore, the industry has breakdown the time fractions into the following water fall model.
OEE Waterfall Demonstration
By breaking down the downtimes with equipment’s total time, the fractions of valued operation time can be seen in a logical order.
The following list contains the net timing for the available OEE fraction
Total time for the production equipment which includes all level of downtime
Equipment time where staff / production personnel are available to operate or monitor the equipment.
Available equipment time for manufacturing. But this will also include the preparation time for setup or productivity loss due to slower speed rate.
Available equipment time for manufacturing and produce required products for the customer.
Available equipment time for manufacturing and produce good products for the contribution.
The following list contains the definitions of OEE downtimes.
These level of downtime consists of either there are scheduled holidays for operation, no demand planned for production line or unavailable loss due to shortage of manpower.
Consists of long period of shutdown from unexpected event to cause equipment failures. Other times such as planned downtime such as engineering trial activities or periodic maintenance are also considered in level 3.
Downtime within process production such as equipment start up (power on), material filling, first article production and line changeover can be considered in this category.
Considered from the production loss either by the rework time or scrap defected products.
For more defined (but not limited to) definition for the different downtimes, please refer to the listed table for the downtime classification. The classification was due to Colin’s industrial experience, the downtime might be slightly different due to different corporation’s classification methodology.
OEE Downtime Example Illustrations
Lastly, for OEE application’s scope can be seen in the graph below for the glimpse of this index application.
OEE Scope Application