Question

Which of the following types of charts is based directly on specification limits?

Option 1: Cusum
Option 2: PRE-control
Option 3: X and mR
Option 4: X and R

Answer 1

Three types of charts commonly used in statistical process control are Cusum, Pre-control, and X and mR (mean and range). Cusum charts are based on cumulative sums of deviations from a target value, Pre-control charts are used when the process operates within pre-defined specification limits, and X and mR charts are used for monitoring the stability of a process.

Step-by-step explanation:

Three types of charts commonly used in statistical process control are Cusum, Pre-control, and X and mR (mean and range).

Cusum charts are based on cumulative sums of deviations from a target value and are used to detect small, persistent changes in a process.

Pre-control charts are used when the process operates within pre-defined specification limits. This type of chart allows for immediate adjustment of a process when measurements fall outside the limits.

X and mR charts are based on the mean (X) and range (mR) of a sample and are commonly used for monitoring the stability of a process over time.