SPC Definition

SPC Definition: SPC stands for statistical process control. Statistical Process Control is a scientific visual method used to monitor, control and improve processes by eliminating special cause variation from manufacturing, service and financial processes. SPC is a key continuous improvement tool.

SPC is also a fundamental tool in six sigma methodology.

SPC Chart Described

The R chart is the bottom chart. The cross hairs represents the range of each data set. They correlate with the cross hairs on the top chart. There is an UC line (and sometimes a LC line) is dependent on the average range of the sample size.

The Y axis for the X bar chart is the average of the sample. The Y axis for the R chart is the number for the range of the sample.

Typically you sample 1 to 8 parts at a set frequency period. You then take the average of the sample size and plot it on the X bar chart. You plot the average in sequence, so the next point will be the furthest to the right. You then take the range of the sample size and plot that on the bottom R chart.

SPC and Special Cause Variation

A SPC chart tells you when your process is out of control. Out of control means there is a special cause that was not there before. This could be an operator setup issue, wrong tooling, a change in raw materials or any unusual noise that can be investigated and eliminated.

By knowing the SPC definition and how to use the charts you improve your processes because it directs you to finding problems exactly when they occur. You can eliminate the noise before process significantly changes. This prevents defects from occurring and costing your company serious $$.

Modern SPC Software

Fortunately, I’ve used the best SPC software in the USA and I used this software for 15 years. The software is the most popular real time enterprise SPC on the market.

• The software adds extensive value to improving your processes.



• The software centralizes the collected data all users have quick access to that data.



• With the software, you can automate data collection and input data from excel, minitab and databases.



• The software package works with any piece of measurement equipment that has digital output. This eliminates data entry errors and decrease data entry time.



• The software includes control charts, histograms and trend charts. You can review the charts one by one or compare several on the same page.






• The software makes advanced SPC charts such as moving average, moving range and cusum.



• The software lets users create custom reports.



• You can output an unlimited amount of statistics. Include these on your custom reports and charts.



• With the software you can create and save custom data filters and statistical filters. These filters let you examine data to fit your needs.



• You can save your favorite charts to desktops and easily review them as needed.



• You design how users enter data into the software. Users do not have to do any calculations. You can design the data entry module to conduct enhance calculations.



• The software stores and tracks all necessary traceabilities with each input. Quickly, you can conduct Anova studies with the tracabilities. This helps you eliminate special cause variation.






• With the software you can make and store multiple control charts with only one data entry session.



• The software monitors the data to quickly identify out of control processes. It can automatically send email to the processes champion. You define the SPC definition monitor rules for each characteristic.



• It allows you to set anchor points, make data notes, and use special characters for data markers.



• The software stores your specifications, allows dynamic and static control limits and provides statistical evaluations quickly.



• If data breaks any SPC definition rule, feedback can automatically be given to the operator for their action.



• You may publish real time data to the web for your customers or other facilities.



• The software provides dashboards for quick management review of the data.