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Statistical Process Control: What Is SPC, What Is It Used for, and What Are the Benefits?

by | Jun 1, 2021 | Uncategorized | 0 comments

Increasing competition has led to process control innovations that ultimately lead to better and cheaper products. Numbers rule the universe, and understanding them opens up all kinds of business opportunities.

Statistical process control (SPC) is about collecting data on production processes, interpreting that data, and using the data to improve the manufacturing process. SPC is used globally to increase profit margins and develop better products.
So, precisely what is SPC, how does it work, and what can it do for your business? Keep reading as we take a closer look at implementing SPC in the production of products.

What Is SPC?

An introduction to SPC should begin with Dr. Walter A. Shewhart. Dr. Shewhart was a physicist for Bell Labs specializing in statistics for small particle behavior before WWII. He is most directly responsible for developing SPC by applying statistical methods to manufacturing process control.

The US Military used SPC to manufacture munitions and other wartime products. Yet, it wasn’t until the Japanese applied SPC to great success that it became a global standard. In recent years, SPC has become a widespread method of perfecting all products.

By plotting production points on a control chart, he noticed some normal variations while others didn’t fit the pattern. These anomalies, among other things, represent inefficiencies in the production process. Researchers use SPC to improve and maximize manufacturing efficiency and quality through data analysis.

Analyzing Statistics

Analysis of this SPC data on control charts puts variations into two categories, controlled (common cause) and uncontrolled (assignable cause). Common cause variations are native to the manufacturing process and can not be controlled. Assignable cause variations indicate that an outside influence in the process is responsible.

Once identified, uncontrolled variables are adjusted to improve the process. All aspects of production management are analyzed, including:

  • Job management
  • Scheduling
  • Data collection
  • Quality control
  • Engineering
  • Machine performance

Epicor® software crunches the data from all these variables and identifies problem areas. Next, we take a look at some of the areas of the manufacturing process that SPC can help improve.


The term engineering encompasses all materials, machines, and human resources used to produce the end product. Project engineers adjust the method of manufacturing (MOM) by revising Part Revisions. The software has a utility called “Engineering Workbench.


Manufacturing operations are constantly having to adjust processes to product demand. Manufacturers must make Many decisions concerning production needs on the fly. With SPC, these decisions are informed choices rather than educated guesses.

The Epicor® ERP software suite includes a powerful scheduling module that will help you fine-tune your planning and scheduling. You can input different scenarios, and the software will crunch the numbers and make suggestions.

Materials Requirements Planning

These powerful software tools are handy for custom order manufacturing. Material Requirements Planning (MRP) is a set of software utilities used to monitor and adjust the materials needed at any given time as needs change. The demand vs. supply of materials on hand and ordering those materials is an important logistical aspect of manufacturing.

When demand is high and materials run low, the software gives amble warning to avoid shutdowns. Future demand is also controlled by inputting variables into the “Master Production Schedule.”

MRP has a vital role in manufacturing, but learning to maximize MRP can be a daunting task due to the complexity and volume of materials in parts involved. We are here to help. Tomerlin-ERP offers Epicor’s® cutting-edge MRP Training and after-sale professional services that will get your people up to speed in no time.

Quality Control

Statistical Quality Control (SQC) is very similar to SPC in that both are processes to improve production quality. The main difference is that SQC includes quality control end data to assess further. Quality control professionals use a variety of tools to identify areas of production that could improve, including:

  • Control charts
  • Scatter diagrams
  • Check sheets
  • Cause and effect diagrams
  • Histograms
  • Data stratification
  • Pareto charts

ERP has Enhanced Quality Assurance modules that make the considerable task of improving rejection rates. Defect rates are a constant enemy of production and often the downfall of manufacturing businesses.

Applications of Statistical Process Control

SPC is used to improve all aspects of every production stage. Speed of production, of course, is essential to manufacturers, but it is not the only element to improve with SPC. Implementing SPC in manufacturing:

  • Increases productivity
  • Increases quality
  • Reduces manufactured defects
  • Reduces energy and material waste

The applications are endless. Every step in the process is essential, and through SPC control, manufacturers can see in the data what needs to be done to improve their operation. If you are not constantly looking to improve production processes in this highly competitive industry, you will soon be pushed out by a company that does.

Work Smarter Not Harder

Technology is advancing at such a rate that manufacturers must adapt or risk joining the reject pile. SPC may seem complicated, especially to those new to process engineering, but SPC is simply an orderly method for breaking down complex systems, understanding the variables, and always looking for ways to improve the process.

Are you ready to take your manufacturing venture to the next level? Tomerlin-ERP is standing by to address all your enterprise resource planning concerns. Call 818-887-9162 or Contact us online, and one of our top industry consultants will fill you in on the details.