What is a Control Chart?

Control Charts Evaluate Process Performance Over Time

Control charts were developed in the 1920's by Dr Walter Shewhart while working at Western Electric Company. Shewhart introduced the control chart as a way to monitor a process and distinguish between:

  • Assignable or Special Cause Variation - needs to be investigated
  • Chance or Common Cause Variation - normal, does not require any action.

Control Charts Contain These Key Elements

Control limits in a control chart.

An Upper Control Limit (UCL) line calculated at 3 sigma above the Center Line.

A line chart of data measuring the process over time.

A Center Line calculated as the average or median of the data.

A Lower Control Limit (LCL) line calculated at 3 sigma below the Center Line.

Think of a control chart as a line graph with built in intelligence that helps you determine what it is telling you.

Three Reasons You Need Software to Create a Control Chart

Control Chart Types

There are seven Shewhart control charts and many more for special situations.

Control Limit Calculations

Each type of control chart has a different formula for calculating control limits.

Stability Analysis Rules

Stability rules identify and highlight points or trends that need to be investigated. They vary by industry.


A 4th reason: control chart software that is affordable and easy to use.

Here is a Control Chart Created Using QI Macros Add-in for Excel

quality control chart created by QI Macros for Excel

I purchased QI Macros just to run control charts (worth the price just for that). I had NO idea what a robust product you have developed, and what an amazing bargain I was getting. File me under exceeded customer expectations. 

- Scott Campbell
SwedishAmerican Hospital

Why Choose QI Macros Over Other Control Chart Software?



  • Only $249 USD - less with quantity discounts
  • No annual fees
  • Free technical support

easy to use

Easy to Use

  • Works right in Excel
  • Create a chart in seconds
  • Easy to customize & share charts

proven and trusted

Proven and Trusted

  • 100,000 users in 80 countries
  • Celebrating 20th Anniversary
  • Five Star CNET Rating - Virus free

QI Macros Unique Features

Control Chart Wizard

Don't know which control chart to run?
QI Macros does.

Control chart selection rules are built right into the code.

choose control chart

Tools Menu Automates Common Tasks

Once you create a control chart, its easy to update or customize it using the Control Chart Tools Menu.

  • Show process changes
  • Add target or goal lines
  • Update and change control limit calculations
  • Update stability analysis
  • Customize charts

Easy to Use Templates for Employees Gathering Data

Drop data directly into the yellow input area and the charts automatically update.


Control Chart Dashboards
Great for Regularly Updating Multiple Charts

One input sheet feeds a dashboard of up to 30 charts.

update monthly control charts

Learn More...