Volume 40, Issue 3 (May 2012)
A Study of Process Quality Assessment for Golf Club-Shaft in Leisure Sport Industries
Effective management of process quality is crucial for attracting customers and maintaining their loyalty, and the quantification of quality for processes with multiple characteristics has recently been receiving considerable attention. This paper proposes a comprehensive process quality index to provide numerical measures for the precision, accuracy, and performance of processes in the manufacturing of golf club-shafts, using both smaller-the-better type and symmetric nominal-the-best type characteristics. The point estimates of these indices were replaced with joint confidence blocks in order to overcome a lack of reliability. Based on this index, we developed a control chart with process capability zones describing joint confidence blocks of all characteristics related to golf club-shafts within a single chart. Finally, we present an assessment procedure and illustrated examples with which to evaluate the process quality for the manufacture of golf club-shaft. The results reveal that the straightness and torsion of the club-shaft are “out of control” and unqualified, whereas the length, tip outer circumference, and butt outer circumference of the club-shaft are categorized as “excessive.” The application of this chart enables engineers involved in the manufacturing of golf equipment to simultaneously monitor and control the quality characteristics of golf club-shafts.