TOPIC: Control limits definition

Rita Mulcahy says "Control charts are established in MQ" and then in the exercise it mentions "acceptable range of Control chart is determined in Plan Quality". What is the difference between both statements. My understanding is that all definitions for quality happen in Plan Quality process and hence control limots would be defined in Plan quality process. Please clarify and explain

Hi Savitri,

Plan Quality Management is the process where you identify quality standards and requirements, and this may include defining control and specification limits; e.g., whether the usual +/- 3 sigma can be acceptable, or a more restrictive measure should be adopted.
Control Charts - as the graphical representation of the variables you measured to describe a given process - are then used as one of the Control Quality Tools&Techniques to determine whether that process is under control.

Gabriella