Process Capability index ('equivalent') taking account of off-centredness
                                                            
                                                     
                        
                                                
                        
                        
                            Centering & spread of the process. A statistical measuring method that is prevention based to provide a zero defect system. 1.65 is a good Cpk
                                                            
                                                     
                        
                                                
                        
                        
                            A statistical calculation of process capability based on the relationship between process variability and design specifications.
                                                            
                                                     
                        
                                                
                        
                        
                            Commonly used process capability index defined as the lesser of USL - m / 3sigma or m - LSL / 3sigma, where sigma is the estimated process standard deviation.
                                                            
                                                     
                        
                                                
                        
                        
                            see Centered Capability Ratio