Question

The Shewhart Chart is another tool that can be used to apply statistical thinking to daily tasks. It is similar to the Run Chart in that it is a graphical display of process variations. For this assignment, discuss what a Shewhart Chart? What makes it preferable to the run chart? What are the 3 questions you need to ask when using this type of chart? Why are these important? What are the 5 rules for the Shewhart Chart? Do you feel this would be a beneficial tool for a healthcare manager?

Answer 1

Shewhart chart is a statistical tool used to measure whether a process is in control or not. In other words it monitors whether a process remains on target and within given upper and lower limits.

A shewhart chart is preferred over run chart as it includes upper and lower control limit lines with a centerline which allows us to go in more detail about the process.

When using shewhart chart one can ask the questions:

• Is the process stable or in control?
• If any of the data is outside the limit lines?
• How much adjustment is required to make it stable?

These are helpful as they indicate the causes that produce deviations from the stable form of the process which is helpful for continual improvement.

Five rules are as follows:

• Large shift-1 point is outside the control limits.
• Small shift-4 out of 5 consecutive points are more than 1 sigma from the center line in the same direction
• Medium shift-2 out of 3 consecutive points are more than 2 sigma from the center line in the same direction
• Stratification-15 consecutive points are within 1 sigma of the center line.
• Mixture-8 consecutive points on either side of the center line with not within 1 sigma.

Yes it is a beneficial tool for a healthcare manager as it helps provide quality healthcare at lower cost with higher effective capacity.