7 QC Tools for Process Improvement | PDF | Case Study (2024)

→ 7 QC tools for process improvement are systematic and scientific methods for Problem Solving and they are used for Product and Process Improvement.

→ It is used to solve 90% of shop floor problems very easily and it improves our workplace.

From Where Did the 7 QC Tools Come?

→ Primarily Kaoru Ishikawa introduced the 7 QC Tools.

→ Ishikawa has known for the “Democratizing (Visual Aids/Symbols) Statistics”.

→ Good visual aids make statistical and quality control more comprehensive.

→ Dr. Kaoru Ishikawa was a professor at the engineering college at Tokyo University.

Why we use The 7 QC Tools for Process Improvement?

→ The 7 QC tools for Process Improvement is a set of graphical techniques identified as being most helpful in troubleshooting issues related to quality.

→ It is used to examine the production sequence, identify the key issues, control fluctuations of product quality, and give solutions to avoid future defects.

→ This facilitates the organization to resolve basic problems.

→ These 7 QC tools are easy to understand and implement and they do not need complex analytical/ statistical competence, hence it is simple yet powerful.

What is the use of 7 QC Tools?

➝ It encourages the way of problem-solving and improvement.

➝ They are very simple to use but it is very powerful.

➝ It is a scientific approach to problem-solving.

➝ We can get an 80% result by applying 20% of the effort.

➝ Each tool has its own specialty for problem-solving and analysis.

➝ It is very easy to understand, communicate, and use by the shop floor operator.

The 7 QC Tools:

1. Flow Charts
2. Cause and Effect Diagram (Fishbone or Ishikawa)
3. Checksheet
4. Histogram
5. Pareto Chart
6. Scatter Diagram
7. Control Chart

Note: We are considering here the Flow chart in this article as a part of 7 Basic QC Tools. Also, you can consider stratification as a part of this tool.

👉Download 7 QC Tools PDF file

[1] Flow Charts:

→“It is a diagrammatic representation that illustrates the sequence of operation to be performed to get the desired result.”

→ It is a visual representation tool for a sequence of operation, therefore, we can easily illustrate the Internal and external operational boundaries.

[2] Cause and Effect Diagram:

→ “It is a meaningful relationship between an effect and its causes."

→ It guides concrete action and tracks the potential causes during an investigation of the effort to determine whether the item significantly contributes to the problem or not.

→ Fishbone diagram can identify all possible cause(s) for the problem.

→ In this tool, we can find possible causes with the help of 6M concepts such as man, machine, material, method, measurement, and mother nature.

[3] Check Sheet:

→ "Check Sheet is a structured, prepared form for collecting and analyzing data."

→ Data collected by the check sheet is used as an input of the other tool and data can be collected based on asking a question by what, when, where, how.

→ The purpose of a checklist is to summarize the data and a tally count of event occurrences.

→ A check sheet counts the number of occurrences of an event, such as defects or non-conformance.

→ Hence the Check Sheet is also called a "tally sheet ".

→ In many cases, a checklist will summarize countable data related to certain types of defects and will provide a rough graphical representation of wherein a part of the process, defects occurred.

[4] Histogram:

→ “Histogram is a type of bar graph representing the frequency distribution of the data from a process.”

→ Karl Pearson introduced Histogram and it is a bar graph representing the frequency distribution on its every bar.

→ Histograms are used to show the output of our process matches the customer's requirements or not?

→ Also, we can take the decision based on the data patterns plotted on the graph either the process is centric or it is widespread.

→ "Is the process capable of meeting customer requirements?“

→ The histogram is the best Frequency distribution tool.

→ A histogram is a pictorial representation of a set of data.

➨ Types of Histogram:

→ Normal Distribution

→ Skewed Distribution

→ Double-Peaked or Bimodal

→ Multipeaked or Multimodal

→ Edge Peaked Histogram

→ Truncated or Heart cut Histogram

[5] Pareto Chart:

→ "It is a bar graph arranged in descending order of height from left to right”

→ It is a graph that shows the order of the largest number of occurrences by item or by classes and the cumulative sum total.

→ The Pareto analysis helps us to prioritize where we can get more benefits by applying fewer efforts.

→ It is also very popular as a prioritization tool.

→ It communicates the principle of 80:20.

→ The Pareto Principle gives us information about Vital few from Trivial many, Hence, It is "Vital few from Trivial many".

→ It states that 80% of an effect comes from 20% of the causes.

[6] Scatter Diagram:

→ “Scatter Diagram is used to study and identify the possible relationship between two variables”.

→ It is the best validation tool.

➨ Different names of the Scatter Diagram:

→ Scatter Plot

→ Scatter Graph

→ Correlation Graph

→ Scatter Gram

➨ Different correlation between two variables in the Scatter Plot:

→ Strong Positive

→ Moderate Positive correlation

→ Weak Positive correlation

→ Strong Negative correlation

→ Moderate Negative correlation

→ Weak Negative correlation

→ Random Pattern (No correlation)