Acme Corporation makes printed circuit boards for the computer
industry.A major part of its process is a copper plating line.Acme
is trying to determine the best method for managing issues causing
downtimes on this production line.You are Acme’s Quality Assurance
Manager.The Quality Engineer has been collecting count data on a
check sheet of causes of downtime for the copper plating line.From
the check sheet, the engineer has provided you with the following
Pareto chart:

You know from the test reports your Quality Technicians prepare
each day that copper thickness is one of the major causes of
defects in your printed circuit boards.Copper thickness is directly
affected by the copper concentration of the solvent used on the
line.There is a concentration requirement for the solvent included
in the technical specifications for circuit boards.You get your
copper solvent from a supplier in Indiana.You have not used this
supplier in the past, and you have very little information about
the supplier’s process for manufacturing the solvent.

Because this is a relatively new production line, you do not yet
have a formal sampling plan or any real-time process monitoring in
place.You have a sufficient budget for your QA department, but by
no means do you have unlimited funds.You are trying to decide
whether to implement Statistical Process Control or Acceptance
Sampling or both. You only have resources available to do SPC on
one factor, if you do it at all.

With all this in mind, answer the following questions:

1.) Would it be prudent to implement Statistical Process Control
to monitor variability affecting the downtime of this line? If your
answer is ‘yes,’ discuss what considerations support implementing
SPC here.

2.) Which factor from the Pareto Analysis do you want to monitor
using SPC control charts, and why did you choose this particular
factor?

3.) Is the factor you chose represented by variables data or
attribute data? How do you know?

4.) Do you want to do acceptance sampling of the circuit boards
coming off this line? If so, what factors lead you to believe
acceptance sampling is proper here?

5.) Assume you decide some acceptance sampling is warranted.
Discuss the characteristics you will want to be sure to include in
your acceptance sampling plan.