Home » Control Charts » ZmR Chart

Trying to Create a ZmR Control Chart in Excel?

QI Macros can create a ZmR chart for you in seconds!

Use an ZmR Chart to:

• Evaluate the Stability of Short Run Processes (Short Run SPC)
• Show multiple characteristics (e.g., hardness, finish, etc.) on one chart
• Track a part as it goes through the manufacturing process

The ZmR Chart does this by converting the X values into a standardized value, Z, using the average (μ) and standard deviation (σ). There are a number of ways to estimate σ. QI Macros uses standard deviation for each part.

Zi = (Xi- μ)/σ

So the UCL = 3, LCL = -3 and CL = 0

---

ZmR Chart data usually looks like this:

To create a ZmR Chart, highlight your "Product" data (col A), along with the "Value" of the product (col B). Then, click on QI Macros menu > Control Charts (SPC) > Variable > ZmR Chart:

QI Macros does the rest.

---

NOTE: If you receive the following prompt, "Invalid Data for ZmR," it is because your data is not sorted:

To troubleshoot this matter, make sure to sort your short run data using the "Sort" function with Excel.

Learn more about Short Run Control Charts

---

QI Macros Draws These Charts Too!