Skip to main content
Cover Image

Proven Benefits of Utilizing SPC in Manufacturing – If SPC is the Answer, What’s the Question?


When you embrace understanding the variation in your process is crucial to your success, you also know that Statistical Process Control is collection of problem-solving tools that will help you achieve your goals.   

Here are a just a few of the questions that SPC can answer for your organization:

  • Are you meeting internal & external expectations?
  • Is your process within Spec? In Control?
  • What is the cause of variation in your process?
  • Would decreasing variation in your process be helpful?
  • Can you be sure your process isn’t drifting over time?


The pressure to increase profits, be it through increased production, reduction of waste or doing more with less, never goes away. Organizations must continually work towards these goals. SPC reduces waste, downgrading, and rework by detecting and allowing operators to correct potential issues before producing bad products. 

Spec vs Control:

The terms specification and control limits are often used interchangeably, but it’s important, especially when using SPC, to understand the difference.

Specification limits, or more colloquially termed Spec Limits, are deemed the voice of the customer, defined by the customer, can be found on histograms applying to items, separating the good items from the bad. 

Control limits, on the other hand, are the voice of the process, calculated from data, are found on control charts, apply to subgroups, are a guide for action and tell us what the process is doing.

Without SPC, you cannot know for sure if your process is in control.

Understanding Your Process:

Good product. Bad Product. That is no longer enough information. A process in spec does not tell you if your process is stable. Unstable processes mean you cannot predict what you will produce. Using tools like SPC to better understand your process increases your ability to produce what you expect to produce, when you expect to deliver it. 

Decreasing Variation:

Variation is a part of manufacturing, but more specifically it is a part of the process. How do you tell the difference between normal variation and something truly wrong? SPC takes the guess work out of process variability by highlighting data points that fall outside of statistical norms. This allows your team to identify next steps to keep the process in control.

Process Drift:

How can you be certain that the process hasn’t drifted from target over time? And if it has drifted, at what rate? The ability to identify drift, understand it and highlight when exactly to adjust can positively impact the process.


SPC is a like a Swiss Army Knife for manufacturers: there are numerous potential applications for SPC across manufacturing processes. This post highlights just a handful of ways that can be applied to help you achieve your goals.