7 quality tools

7 quality tools
See also
Six sigma Deming wheel Decision tree Pareto chart Quantitative risk analysis Statistical process control Diagnostic approach Affinity diagram Why why analysis

7 quality tools were created by quality practitioners over the years and collected in one group in early 50s in Japan. Along with the quality movement they were popularized as quality tools. Development of quality methods and techniques lead to creation of new set of quality tools, which extended the older one.

7 Traditional quality management tools

Traditional tools are called Magnificent seven. They are the most commonly used and they are of fundamental importance. These tools can be used on its own, but often are used as components of quality management methods. They are based on simple mathematics and statistics. Therefore, they are often called statistical process control tools. The tools include:

• Fish diagram - cause and effects diagram used to find many levels of causes of analysed result
• Check sheet - helps collecting data about quality in the process
• Control chart - shows variability in the process and helps to analyse it.
• Histogram - enables to show on chart the distribution of data. In controlled process it usually looks like Gauss curve (normal distribution)
• Pareto chart - shows the most important elements of the group according to chosen criteria. It uses the 80-20 rule.
• Scatter diagram - shows correlation between two variables
• Flow chart - chart presenting flow of the process.

7 new quality management tools

Along with the development of quality management 7 new tools were created. They were designed to enhance traditional tools. They enable a better information flow in the enterprise. They are very important when solving problems.

They include:

• Affinity diagram - finding relationships between ideas
• Relations diagram - diagram showing causal relations between aspects of complex situation
• Matrix diagram - shows relationships between many variables using many dimensions
• Matrix data analysis -
• Arrow diagram - used to show the flow of process or project, similar to CPM method
• Tree diagram - breaks down categories into subcategories, parts, elements, etc.
• Process decision programme chart - identifies what may go wrong during realization of the plan.

Advantages of 7 quality tools

The 7 quality tools are a set of tools used to support problem solving and decision making in the quality management field. They are: Cause and Effect Diagram, Check Sheet, Control Chart, Histogram, Pareto Chart, Scatter Diagram, and Flow Chart. These tools provide the following advantages:

• Cause and Effect Diagram: This tool helps to identify the root causes of a problem and trace effect relationships.
• Check Sheet: This tool helps to collect and organize data in order to identify certain trends and problems.
• Control Chart: This tool helps to monitor process performance over time and identify any points of variation.
• Histogram: This tool allows for quick visualization of data distribution and helps identify any potential outliers.
• Pareto Chart: This tool helps to identify which factors are contributing the most to a problem and helps prioritize solutions.
• Scatter Diagram: This tool helps to identify any possible correlations between two variables.
• Flow Chart: This tool helps to clearly map out a process and identify any potential bottlenecks.

Limitations of 7 quality tools

The 7 quality tools are a collection of quality methods and techniques used by quality practitioners since the 1950s. However, these tools have a few limitations:

• They are primarily focused on the cause-and-effect analysis and process improvement, which limits their usefulness in identifying and addressing more complex problems.
• They are not able to provide a comprehensive view of the entire system and are not suitable for predicting the effects of changes in the system.
• They lack the ability to provide an accurate and timely diagnosis of problems, which can lead to incorrect conclusions and decisions.
• They are not suitable for measuring customer satisfaction, as they do not measure customer feedback and preferences.
• They can be difficult to use for non-experts, as they require a certain degree of knowledge and understanding of the system.

Other approaches related to 7 quality tools

In addition to the 7 quality tools, there are other approaches related to quality improvement that have been developed by quality practitioners over the years. These include:

• Statistical Process Control (SPC) which is a method of monitoring and controlling a process by collecting and analyzing data to detect and prevent process problems.
• Total Quality Management (TQM) which is an organizational approach to quality improvement that seeks to involve all stakeholders in improving processes, products, and services.
• Lean Manufacturing which is a process improvement method that seeks to reduce waste and increase efficiency.
• Six Sigma which is a set of techniques and tools for process improvement that focuses on reducing variation and defects.
• Design of Experiments (DOE) which is a method of using controlled experiments to determine the best way to design a process or product.
• Measurement System Analysis (MSA) which is a method for evaluating and improving the accuracy and precision of a measurement system.
• Failure Mode and Effects Analysis (FMEA) which is a method of risk management that seeks to identify and address potential failure modes in a process or product.

Overall, these approaches are used to improve quality processes, products, and services and are often used in combination with the 7 quality tools.

References

• Wilkinson L (2006) Revising the Pareto Chart, The American Statistician, Volume 60, Issue 4
• Salih O. Duffuaa, Mohamed Ben‐Daya, (1995) Improving maintenance quality using SPC tools, Journal of Quality in Maintenance Engineering, Vol. 1 Iss: 2