What is the first step that should be taken if an observation falls below the lower control limit on a control chart?
A) Recalibrate the machine
B) Perform a new process capability study
C) Try a larger standard deviation value
D) Search for assignable causes
E) Nothing-a low value is a "good" thing

Question

Quizplus · Accepted Answer

If an observation falls below the lower control limit on a control chart, it indicates that the process has gone out of control. The first step should be to search for assignable causes, which are specific factors that are responsible for the variation in the process. Once identified, these causes should be eliminated to bring the process back under control. Recalibrating the machine or trying a larger standard deviation value may not address the underlying cause of the problem, while performing a new process capability study is a more comprehensive solution that is better suited for assessing long-term process performance. Doing nothing, as suggested in option E, is not a viable option as it will allow the process to continue producing out-of-spec products.

What Is the First Step That Should Be Taken If