The reason(s) for not marking the customer Specification Limits (SL) on a Control Chart is which of these? (Note: There are 4 correct answers).

Question

Quizplus · Accepted Answer

A) Process control teams should focus on controlling a process based on its inherent variability, rather than simply monitoring to meet upper and lower specification limits.

B) Displaying the SLs on a Control Chart may focus attention on meeting those limits alone, rather than reducing variation in the process.

C) Marking the SLs on a Control Chart could be considered adding unnecessary information, as they are not used to calculate Control Limits or identify special cause variation.

D) By marking the SLs, operators may assume that staying within the SLs is enough to ensure stable, high-quality output, or may prioritize meeting those limits over reducing process variation.

E) Statistical Process Control (SPC) focuses on understanding and reducing inherent variability in a process, rather than simply staying within set limits. Simple control limits are sufficient to identify when a process is in a state of control and when special cause variation may be present, without adding unnecessary complexity.

The Reason(s) for Not Marking the Customer Specification Limits (SL)