| 摘要 |
<p>The product has specified performance characteristics, and is manufactured using a plurality of constituents. A set of properties of the constituents which affect the product performance characteristics is defined, sampling data on the set is determined, and a model is defined using the sampled data in terms of parameters T 2 and Q res where T 2 is derived from the sum of the squares of each of the principal components of the model, and Q res is derived from a weighted sum of squares of principal components not included in the model. The derived T 2 value is compared with a standard for that product and, if the value of T 2 exceeds a predetermined limit, there is an indication that there has been a significant change in the typical properties of the constituents. The relevant constituent and property can be determined, and action can be taken to replace defaulting constituents prior to manufacturing.</p> |
