----------------------------------------------------Business Index & ASAP------
AUTHOR(s):       Beard, Thomas L. 
TITLE(s):        SPC is no guarantee of quality. (statistical process
                   control) (column)                                          
                 Modern Machine Shop 
                 p36(1) 
                 April  1989  v61  n11   
DESCRIPTORS:     Statistical process control_Usage 

   SPC Is No Guarantee Of Quality                                              

     A gentleman called the other day with a point to make. He had just        
   read an article on SPC in our February issue which emphasized quality       
   control. The point was, and is, that statistical process control is not     
   synonymous with quality.                                                    
     He's quite right about that of course. The use of SPC techniques does     
   not guarantee anything, including quality production. There is probably     
   no better tool, but the maintenance and improvement of quality in           
   manufacturing requires more than good tools.                                
     Foremost, it requires a shop floor culture that is intolerant of poor     
   quality. And it requires a bias for action to improve quality. Shop         
   floor people should be appalled at the sight of a non-conforming part.      
   But most important, they should be personally motivated to do something     
   to prevent it from happening again.                                         
     To be of much help, though, people need to know what to do. They need     
   training. They need to understand how to identify a wavering process,       
   and know what corrective action to take.                                    
     An operator should be responsible for quality, but should not feel        
   that he or she alone is concerned with its pursuit. The culture of          
   quality begins at the top and then permeates every level of the             
   organization. The effort is rarely sustained when approached the other      
   way around.                                                                 
     So what does SPC have to do with all this? It is the best tool going      
   to enable shop floor people to exercise authority over the processes to     
   which they are charged. It is a means by which operators receive            
   confirmation, not just when something has gone wrong, but also when         
   things are going right.                                                     
     And it is a tool that can show what is happening in the manufacturing     
   process as it is happening. This "real time" monitoring tool is a           
   critical element of a quality program that strives for zero defects, the    
   ultimate goal.                                                              
     Like any tool, statistical process control is only as good as the         
   people who use it. SPC does put control into the hands of the only          
   people who can guarantee quality, those who make parts. But they must be    
   prepared to exercise that control, and know that management will            
   support their assumption of a more responsible role.