5.3 The Knowledge Management Solution 129
The SPC System
The Statistical Process Control system is a database for recording the
results of SPC studies (that is, Process Capability studies and Machine
Capability studies). It includes a feature for predicting process capa-
bility for user-defined tolerances using CBR. Given the upper and
lower tolerances (U.S.L and L.S.L), the system calculates the midpoint
and applies nearest neighbor techniques to find the predicted process
capability (CPK) from the best matching cases. (See Figure 5.3.) The
predicted value is calculated by adapting the CPK value from the past
case to fit in with the user’s new tolerances. ...