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I-MR Chart Maker

Here you can easily create an I-MR Chart online! Just copy your data into the table and select the measurements.

I-MR Chart Maker

The I-MR Chart will then be created for you online.

Create I-MR Chart online

Create an I-MR Chart online

In Statistical Process Control (SPC), an I-MR Chart, also known as an Individuals and Moving Range Chart, is a type of control chart used to monitor the stability and variation of a process when individual measurements are taken. The chart consists of two components: the I Chart (Individuals Chart) and the MR Chart (Moving Range Chart).

I-Chart (Individuals Chart):

  • The I-Chart displays individual data points over time, with each point representing a single measurement or observation from the process being monitored.
  • A center line is drawn on the chart to represent the average or mean of all the individual data points.
  • Upper and lower control limits are also plotted on the chart, typically set at a certain number of standard deviations (usually three) from the center line.
  • The I-Chart helps monitor the variation of individual data points and detect any patterns or trends that may indicate process instability.

MR Chart (Moving Range Chart):

  • The MR Chart displays the moving ranges between consecutive data points on the I-Chart.
  • Moving range is calculated by taking the absolute difference between consecutive data points: MR = |Xi - X(i-1)|, where Xi is the current data point and X(i-1) is the previous data point.
  • A center line is drawn on the MR Chart to represent the average or mean of all the moving ranges.
  • Upper and lower control limits are also plotted on the MR Chart, typically based on statistical methods appropriate for moving ranges.
  • The MR Chart helps monitor the variation between consecutive data points and assess the stability of the process.

Interpretation of the I-MR Chart involves analyzing both the I-Chart and the MR Chart:

  • In the I-Chart, if data points fall within the control limits and show random variation around the center line, the process is considered to be in control.
  • In the MR Chart, if moving ranges fall within the control limits and show random variation around the center line, it suggests that the process is stable.

The I-MR Chart is commonly used in industries such as manufacturing, healthcare, and finance to monitor and improve processes, identify potential issues early, and make data-driven decisions for process improvement.

Cite DATAtab: DATAtab Team (2025). DATAtab: Online Statistics Calculator. DATAtab e.U. Graz, Austria. URL https://datatab.net

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