At ZYZ Company, a custom manufacturer of printed circuit boards, the finished boards are subjected to a final inspection prior to shipment to its customers. As XYZ’s quality assurance manager, you are responsible for making a presentation to management on quality problems at the beginning of each month. Your assistant has analyzed the reject memos for all the circuit boards that were rejected during the past month. He has given you a summary statement listing the reference number of the circuit board and the reason for rejection from one of the following categories:
A= Poor electrolyte coverage
B=Improper lamination
C= Low copper plating
D= Plating separation
E= Improper etching
For 50 circuit boards that had been rejected last month, the summary statement showed the following:
C B C C D E C C B A D A C C C B C A C D C A C C B
A C A C B C C A C A A C C D A C C C E C C A B A C
a. Prepare a tally sheet (or checklist) of the different reasons for rejection.
b. Develop a Pareto chart to identify the more significant types of rejection.
c. Examine the causes of the most significant type of defect, using a cause-and-effect diagram.
