The yield performance starts with selection of the right raw material. If you are selling a butchered shoulder that is allowed to contain 20% fat, then attaining the optimal yield is going to be difficult if you are utilising a lean raw material.
A shoulder that has a subcutaneous fat level of 10mm will yield 44.86% finished shoulder, but a shoulder that has a subcutaneous fat level of 15mm will yield 45.88%, butchered to a 20% specification. The difference is obviously fat, but if the specification allows for the additional fat, then you are returning shoulder price for you fat rather than fat price.
If the specification only allows 10% fat in the finished product, then the logic is reversed. A shoulder with 10mm subcutaneous fat will yield 38.99% finished shoulder - where the 15mm will yield 36.87%.
The effect on return price is an increase 1.3% (depending on sales prices) as you are selling less fat (as fat) in both instances. All the costs are exactly the same, as all you have done is chose the best raw material for the specification in question.
However, you can only obtain the return if you have the right carcass selection and are using the right method of grading.
This logic applies to all carcasses and all products. Weight selection and size selection is also a factor in European countries where a lot of the products are sold at a predetermined weight i.e. fixed weight products.
The earlier in the process you can establish the suitability of the product the more revenue you will be able to generate with the same raw material.