Which one of the following statements is TRUE?
◦ No two products are exactly alike because the processes that produce them contain many sources of variation, even if the process is a machine.
◦ Common causes of variation are those factors that can be identified as commonly occurring at a particular process.
◦ SPC and TQM are two competing techniques for quality control.
◦ With due diligence, variation in a process can be completely eliminated.