The Seven Quality Control Tools: A Practical Guide

The Seven Quality Control Tools are an essential part of any quality management system. They provide a comprehensive and effective way to identify, analyze and address problems associated with product or process design and development.

This practical guide explains the fundamentals of each tool, including why they are important, how they can be used in practice, and what results can be achieved from their application.

It also provides tools for assessing the suitability of different approaches for specific situations and guidance on the selection of appropriate methods when faced with multiple options.

Importance of Quality Control in Business

Quality control is implemented in order to ensure that products are safe, reliable, and meet customer expectations. By conducting quality checks on both incoming materials as well as finished products, businesses can detect any problems early on and take corrective action before they become significant issues. Furthermore, businesses can use feedback from customers to ensure their processes remain effective over time.

The Seven Quality Control Tools

Check Sheet

The check sheet is a quality control tool that can be used in many different ways. It allows for the collection and analysis of data, which then enables companies to identify problems and take corrective action.

This helps to ensure that quality products are produced and services are delivered without defects. Check sheets also assist with tracking processes, measurements, materials, or other activities related to manufacturing or service delivery.

The information collected on the check sheet can help determine if there are any errors in production or service delivery that need to be corrected before it reaches customers. Additionally, they provide valuable insight into process efficiency as well as customer satisfaction levels so that further improvements can be made over time.

All of these benefits make the check sheet a powerful quality control tool for any organization looking to improve its operations.

Cause and Effect Diagrams

Cause and effect diagrams, also known as Fishbone or Ishikawa diagrams, are a quality control tool used to identify the root causes of defects in processes. These diagrams provide a visual representation of the relationships between different components of a system, allowing users to identify potential sources of errors and determine corrective actions.

Through careful analysis of existing process elements, teams can uncover major points where problems may arise. Cause and effect diagrams are essential for pinpointing underlying issues that need resolution before they become full-blown issues.

They can be used when brainstorming solutions by helping teams think through possible causes and effects associated with proposed changes. Additionally, these tools have been shown to reduce time spent troubleshooting problems while increasing team collaboration on projects.

By utilizing cause and effect diagrams during the development cycle, organizations can effectively monitor their systems for weaknesses or areas in need of improvement.


Histograms are one of the most useful tools in quality control. They provide a visual representation of data that can be used to identify important characteristics such as outliers, patterns, and trends. Quality control personnel use histograms to quickly detect anomalies or undesired processes within their systems.

Histograms can also be used for decision-making regarding process parameters and product specifications by providing a graphical representation of the distribution of data points.

By plotting various pieces of information into a single graph, it is possible to gain insight into how different variables may affect each other and how they may relate to overall performance or quality standards.

Histograms are an essential tool in any successful quality control program as they allow organizations to quickly identify problems before they grow out of hand and adversely affect operations.

Pareto Chart

The Pareto chart is a simple yet powerful tool used in quality control and process improvement. It was developed by Vilfredo Pareto, an Italian economist who discovered the 80/20 rule, or that 80 percent of the effects come from 20 percent of the causes. The chart takes this principle and applies it to problem-solving.

Organizing data into bars according to the frequency of occurrence helps identify which areas are causing the most problems so that corrective action can be focused on them.

For example, if defect rates as shown in a Pareto chart indicate that four out of five defects were caused by two different types of failures, then resource allocation for improvement efforts should focus on those two failure types instead of addressing all potential contributors equally.

Additionally, since the chart visually displays how much each factor contributes to overall performance issues, it allows managers to easily compare solutions and make informed decisions about where resources should be invested first.

Control Chart

The Control chart is a popular quality control tool used to track process performance over time. It is based on the idea of Shewhart’s statistical process control (SPC) and helps identify when processes are not performing as expected.

With this tool, organizations can monitor key performance indicators such as cost, throughput, defects, or downtime to detect any significant changes in the system that could indicate a problem.

This allows them to take corrective action before any further issues arise. The Control chart also provides useful information about how different parts of a system interact with each other, allowing for more efficient improvements and better decision-making.

Scatter Diagram

A scatter diagram, also known as a correlation graph or scatter plot, is an effective quality control tool that helps visualize the relationship between two variables. The x-axis of a scatter diagram typically represents one variable while the y-axis represents another variable. Points are plotted on the chart to indicate where each set of data points falls in relation to each other.

This type of visual representation can quickly identify any patterns or correlations between two variables and help determine if there is cause for further investigation into what may be causing variability in either one or both values.

A wide variety of metrics can be examined, such as product performance versus cost, customer satisfaction versus time taken to complete a task, variance observed from different production runs over time, etc., making this an incredibly useful tool for QC teams everywhere.


Stratification is a powerful quality control tool used to analyze the composition of a sample. It is typically used when investigating differences in characteristics between two or more groups. Stratification can be used to help identify potential causes or sources of variation within the sample, and it allows for comparison between different levels or strata by dividing them into distinct subgroups.

Stratification provides an easy way to detect patterns that might otherwise go undetected, and it can provide valuable insight into how variables interact with one another in complex situations.

In addition, stratification can also allow researchers to make better decisions regarding which populations should be studied further, as well as what types of data should be collected from each group for statistical analysis purposes.


The Seven Quality Control Tools are an important set of tools for any business to have in their quality control arsenal. They allow businesses to quickly identify, troubleshoot, and solve problems that can arise in the production process.

By using these seven tools together, businesses can ensure that they are producing the highest possible quality product at all times. This guide has provided a comprehensive overview of each tool and how it is used. With this information, businesses should be better equipped to utilize these powerful tools successfully within their own organization.

Updated on: 15-May-2023


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