What categories of QUALITY are there
OEE Coach distinguishes four output categories for measuring the quality rate and to make subsequent analyses:
- G: Good Output
- S: Scrap
- SS: Sub-Spec
- R: Rework
Each output type is explained below.
P: Good Output
Output is assigned a [G]ood Product when it meets the quality specifications. This entails more than just the question whether or not this product is delivered to the customer!
Output is assigned a [S]crap when it does NOT meet the quality specifications, and cannot be sold. The value, added to the product, will not be paid for. On top of this, more costs are added for removing the scrap. By making this loss evident we are forced either to revise our specifications or to bring the process under control.
Output is assigned a [Sub-Spec] when it does NOT meet the quality specifications, but the product is sold to the customer (or another customer e.g. in another market) as B quality. The value, added to the product, might not be paid for totally, and the profit is reduced or even a loss. On top of this, more costs are added for supporting an organization for a non-core business market etc. By making this loss evident we are forced either to revise our specifications or to bring the process under control.
Output is assigned as [R]ework when it does not meet the quality specifications but can be reprocessed into products that will meet the quality specifications. At first sight reworking products does not seem to be such a bad thing, for you can still sell the product at the normal price. However, in terms of the OEE, rework is just as bad as scrap: the product was not right first time. It also implies that losses have occurred: you will have to incur additional costs for labor, energy, and other actions in order to correct the product.
Loss of quality is the most expensive form of incurring losses since both time and materials have now been used and the product cannot meet the wishes of the customer. Moreover, extra expenses and effort, outside the production and organizational process of the ‘good Output’, have to be made to deal with the scrap and rework products. This also clarifies why reprocessing is in fact a disaster: All expenses have already been made and still more money needs to be spent on additional treatment, separate routing, temporary storage etc. going once again through a partial or entire production process! Therefore, these products are very expensive while the organization often does not realize this …