In his 1990 bellwether Introduction to Quality Control, Ishikawa stated: “They were named the Seven QC Tools after the famous seven weapons of the Japanese Kamakura-era warrior-priest Benkei which enabled Benkei to triumph in battle; so too, the Seven QC Tools, if used skillfully, will enable 95% of workplace problems to be solved. In other words, intermediate and advanced statistical tools are needed in about only 5% of cases.”
What are these seven weapons? Let’s look more closely at the Seven Basic Quality Tools:
Juran defined this tool with the rule of 80%-20% to classify problems from “vital few” to “trivial many.” This is a useful tool that helps to provide priority among many problems – 20% of which represent the opportunity for 80% of the improvement. In all DMAIC projects, it is a starting point to define which problem to attack at first.
Cause & Effect Diagram
Also known as a Fishbone diagram or the Ishikawa diagram, the Cause & Effect Diagram is useful to find the root causes of a problem. In a manufacturing problem, this tool is often applied by identifying the 5Ms as potential areas for cause – Men, Machines, Materials, Method and Measurement.
The Histogram is simply a bar chart graph that shows the number of times a particular outcome range occurs. Used as a quality tool, it shows the distribution of outcomes, and reveals causes most often associated with a result.
A control chart shows how a process is changing over time. Plotting results over time, the control chart shows the average value of the measured attribute, with a line showing the upper acceptable limit and the lower acceptable limit. It is a quick way to see whether a process is operating properly, or trending out of spec.
Also knows as a scatter plot, the scatter diagram plots the relationship between two process variables, one on the X axis and one on the Y axis. It is a quick way to see a correlation, or the tendency of one variable to have an effect on the other.
Multiple types of graphs are visual representations of process performance. They allow trends in processes to be quickly detected.
The check sheet is simply a point of data collection in real time at the source. The data can be qualitative or quantitative.
Even though these tools were classified twenty years ago, they are far from obsolete. In fact, they are still the starting point for all quality evaluation of root cause analysis.
How does Siemens Opcenter Quality (formerly known as QMS Professional) support quality work with the quality tools?
As the age of Industry 4.0 is now upon us, machines and systems are being networked, and they communicate with each other to produce individual pieces as well as mass-produced goods. Using a company-wide quality management solution like Siemens Opcenter Quality, a quality team manages interdisciplinary cooperation and achieves the transparency needed to pursue a zero-defect strategy. What type of system support do your employees have in quality management to reduce quality costs and warranty costs, and approach zero-defect performance?
With Siemens Opcenter Quality (formerly known as QMS Professional), these weapons are at your fingertips.
In one example of a Siemens Opcenter Quality (formerly known as QMS Professional) application, a manufacturer is now employing:
- Automatic complaint creation from shop floor, web portal, and customer complaints
- Hierarchical defect analysis based on 8D methodology
- Creation of Ishikawa diagram and 5Why method
- Integrated action management
- Repeated defect detection and continuous improvement process
- Real time evaluation and reporting
These capabilities provided by Siemens Opcenter Quality (formerly known as QMS Professional) create an end-to-end, closed-loop quality solution. With this approach, manufacturers are able to ensure that all data, whether coming from a machine, human or test, are being consolidated in one, always available, easily accessible system.
Now, Tools for quality management are available in a single system, and available to be integrated into your manufacturing operations from beginning to end.
Learn how Siemens Opcenter Quality (formerly known as QMS Professional can empower your quality management system.
Ishikawa, Kaoru (1985). What Is Total Quality Control? The Japanese Way. Translated by Lu, David J. (1st ed.). Englewood Cliffs, New Jersey: Prentice-Hall. ISBN 978-0-13-952433-2.
Ishikawa, Kaoru (1990). Introduction to Quality Control (1st ed.). Tokyo: 3A Corp. ISBN 978-4-906224-61-6.