Statistical Control Process: is it Right Business Strategy For You?

Here in this blog we are going to share with you everything about statistical control process. And give you the answer the is it the right business strategy for you.

Background of Statistical Process Control (SPC)

In 1920, Dr. Walter Shewhart of Bell Laboratories developed the concept of Statistical Process Control, and then it was expanded by Dr. W. Edwards Deming. After that, this methodology was used by Japanese firms after the Second World War, and now it is used by all the organizations around the world to keep a check on their process and product to earn profits.

Definition of Statistical Process Control

Statistical Process Control can be defined as the scientific methodology to monitor and control the product and process method.

Meaning of Statistical Process Control

Statistical Process Control is a statistical method to measure, control, and monitor the process to ensure the efficiency and effectiveness of the product and process. Since the variation is an inherent part of a process, whether it is manufacturing or service etc. therefore, the organizations use different methods and tools to control such variation to get desired results. SPC is the primary tool to detect even the small variation in a process so that corrective and preventive steps can be taken to control the process.

Statistical Process Control Chart

The Statistical Process Control Chart is also called a Shewhart chart. It is the primary tool of SPS. It is in the form of a graph in which data and control limits are plotted to analyze the variation in the process. Besides, it manifests three lines to show the variation level; these are the central line for the average control limit, the lower line for the lower control limit, and the upper line for the upper control limit. These limits are evaluated as per the historical data. After that, the present data are compared with these lines to conclude the efficiency of the process.

 Steps involved in SPC Chart

Firstly, the organization establishes a process to evaluate the key areas of waste like rework, scrap waste, etc.

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Secondly, the period during which such a process is to be evaluated must be determined concerning variation in Man, Material, Method, Movement, Machine, and Environment.

At last data will be collected on the predetermined key areas of the process

After that, the data collected and the predetermined control limits are plotted on a graph (i.e., Statistical Control Chart) for analysis.

If the data confines under the control limits, then it implies that the process is operating as expected. Even if there is any variation, then that is due to a common or natural cause. But if the data is outside the control limits, it implies that the process is not operating as expected due to unforeseeable factors and needs to be fixed before the actual defect occurs.

Other Statistical Process Control Tools

1) Check Sheet

It is a simple structured document to collect the data in real-time. and at the place where the data is generated and analyze the defects that arise so that these defects can be timely cured.

2) Stratification

It is a type of flow chart which shows the whole process in steps through boxes. This tool divides the data, people, and objects into distinct groups. It thus gives the visual representation of the process, which helps analyze the whole process quickly and find out the defects therein.

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3) Scatter Diagram

This tool is used to study the possible relationship between two variables through a graph. It helps to understand the relation between the two variables and the strength of the same. Under this method, if data is scattered close to a trend, it depicts the strong relation or vice-versa. And if the data is randomly scattered. Then there is no correlation between such variables.

4) Histogram

It shows the variation in the process by showing the frequency of occurrence of given data. That is why it is also called Frequency Distribution. Thus, it helps to draw conclusions about the distribution of the output of a process or about the customer’s requirements or to check whether any variation has occurred in the process and so on.

5) Pareto Chart

It is a kind of Bar Graph in which the longest bars are shown at the left. And the shortest bars on the right side. It represents the frequency of cost, time, or money. And it is evaluated through the size of the bar. Preto is used to analyze what is the frequency of any problem or defect in the process and what are the critical areas to be focused on.

6) Cause and Effect Diagram

It is also known as Fishbone Diagram. This tool states all the causes of a particular effect or problem in a process. It prescribes the major heads of causes of any problem like Machine, Material or Manpower, etc. After that, subheads of all causes related to it are listed under each main head. So whenever any variation is suspected in the process. The organization can detect the cause of such a problem or effect through this diagram.  

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Advantages of SPC

  1. It is a statistical method to track the process to know whether the process is in control, which ultimately ensures the efficiency of the process.
  2. It helps to detect even the small changes in the process so that corrective and primarily preventive measures can be taken before the changes arise.
  3. SPC will lead to reduced scrap and rework and thus reduces the cost.
  4. It helps to make real-time decisions instantly.
  5. SPC helps to have the edge over the competitors in today’s competitive world.
  6. Importantly, it will improve the overall quality and productivity level of the products. 

Statistical Process Control Software

SPC Software performs the complete procedure of SPC methodology. It collects the quality and performance-based data of the organization in real-time. SPC then statistically analyzes the same to detect the variation in the process to take preventive actions before such variation occurs. It will maximize operational performance.


Statistical Process Control is a statistical method to control and monitor the process to evaluate the issues related to such a process beforehand by comparing through control limits so that corrective measures can be taken to avoid such special causes. It consists of various tools to make this method more efficient. It will help the business improve its quality and productivity, save the cost and time of the business, and maximize the business profits. Therefore, we can say that it is one of the best strategies for a business to control and monitor its processes. If you want then you can get CPM statistics homework help from us at affordable prices.