TDC - Bottleneck-Factor Category
This category is a 'one time' entry of a constant, updated annually. Most have not identified all the bottlenecks in their systems, and the percentage of each affects their production. Your existing method of calculation need only meet the TDC recommendations below.
After visiting 100s of paper plants, I have seen the same misconception. It is well known that the corrugator is a bottleneck, because the entire facility is itís downstream. So much so, they will run at top speed (not necessarily most efficient speed), with speed indicator in the production managerís office.
In many of those facilities, all material will flow through a single strapper, or conveyor, but these do not get a tenth of the investments of resources that the corrugator does. With this example the facility becomes a push production process, with storage, scrap, multiple handling, labor, etc., being the buffer and profit loss. With TDC, the question would no longer be "how can we have record production rates off of the corrugator while having reduced sales, quality, safety, and profits?"
The other bottleneck examples above, like an air compressor, are not realized in the day to day management decisions, until the unrecognized bottleneck shuts down the facility, or a large portion thereof.
As time goes by after a bottleneck makes itself know, it once again drops out of the spotlight in the daily decisions. Actually a bottleneck should be identified and classified, hopefully before a failure, but a least afterwards. This is one of the key advantages of the TDC method, and one of the greatest cost savings too.
Ironically, TDC represents the final bottlenecks to a fully integrated and auditable approach to maintenance strategy development / justification.