Unit I - Introduction To Quality and Quality Tools
Unit I - Introduction To Quality and Quality Tools
Unit I - Introduction To Quality and Quality Tools
INTRODUCTION
There are seven basic quality tools, which can assist an organization for problem
solving and process improvements. The first guru who proposed seven basic tools was
Dr. Kaoru Ishikawa in 1968, by publishing a book entitled “Gemba no QC Shuho” that
was concerned managing quality through techniques and practices for Japanese firms.
It was intended to be applied for “self-study, training of employees by foremen or in QC
reading groups in Japan.
Figure 1 indicates the relationships among these seven tools and their
utilizations for the identification and analysis of improvement of quality
These seven basic quality control tools, which introduced by Dr. Ishikawa, are :
1) Check sheets;
2) Graphs (Trend Analysis);
3) Histograms; 4) Pareto charts;
5) Cause-and-effect diagrams;
6) Scatter diagrams;
7) Control charts.
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1. Check Sheet
Check sheets are simple forms with certain formats that can aid the user
to record data in an firm systematically. Data are “collected and tabulated” on
the check sheet to record the frequency of specific events during a data
collection period. They prepare a “consistent, effective, and economical
approach” that can be applied in the auditing of quality assurance for
reviewing and to follow the steps in a particular process. Also, they help the
user to arrange the data for the utilization later .
The main advantages of check sheets are to be very easily to apply and
understand, and it can make a clear picture of the situation and condition of
the organization.
They are efficient and powerful tools to identify frequently problems, but
they don’t have effective ability to analyze the quality problem into
the workplace. The check sheets are in several, three major types are such
as Defect-location check sheets; tally check sheets, and; defect-cause check
sheets .
Figure 2 is depicted a tally check sheet that can be used for collecting
2. Histogram
3. Pareto Analysis
To expand on this definition, let’s break a Pareto Chart into its components.
2) Each bar usually represents a type of defect or problem. The height of the bar
including Collar Defects. In this case, this would be the sum of the percentages
of Button Defects, Pocket Defects, and Collar Defects (39% + 27.1% + 16.9%).
FREQUENCY % OF CUMULATIVE
TYPE OF DEFECT
OF DEFECT TOTAL %
Total 59 - -
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In the example above, solving just the two most important types of defects — Button
Defects and Pocket Defects – will remove 66% of all defects.
In any Pareto Chart, for as long as the cumulative percentage line is steep, the types of
defects have a significant cumulative effect. Therefore, it is worth finding the cause of these
types of defects and solving them. When the cumulative percentage line starts to flatten, the
types of defects do not deserve as much attention since solving them will not influence the
outcome as much.
First, the first bars are always the tallest, indicating the most common sources of defects.
Second, the cumulative percentage line indicates which defects to prioritize to get the most
overall improvement.
6) The Pareto Principle can analyze Pareto Charts, also known as the 80/20 rule.
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4. Fishbone Diagram
5. Scatter Diagram
6. Flowchart
7. Control Chart