When used in well-defined domains, their ability to generalize and learn from data mimics our ability to learn from experience. However, there is a drawback. Unlike a well-planned and executed DOE, a neural network does not provide an explicit mathematical model of the process. For example, in addition to feeding the neural net X 1 and X 2 raw, one could include transformations, higher-order polynomial and interaction terms, etc. as inputs to the neural network. Still, for the most part, neural networks must be approached as black boxes with mysterious internal workings, much like the mystery of the human mind it is designed to imitate.
All companies record important data, some in well-designed data warehouses, some in file drawers.
This data represents potential value to the Six Sigma team. It contains information that can be used to evaluate process performance. The activity of sifting through a database for useful information is known as data mining . The IS department may already have compiled this information. Determine the variables which apply to the process being improved and for which historical data exist.