Histogram: The way of data analysis and QC tool

As been a Quality Engineer or Industrial Engineer we must know the 7 QC tools. And one of the important QC tool is Histogram.

In this post you will learn more details about this tool. How and the way of data analysis using the important QC tool.

Table of Contents

What is Histogram?

Histogram is the visual tool for presenting the variable data. And also it organize the data to describe the process performance.

Additionally it shows the amount and pattern of the variation from the process. The date you collected will be arrange in manner, it will show you the variation and spread of data.

Therefore it is the most powerful tool in 7 QC tools.

Why do we get variation?

Variation is essentially a law of nature. Therefore we can’t eliminate the variation.

Output quality characteristics depend upon the input parameters.

It is impossible to keep input parameters constant. There will be always variation in the input parameters. Since there is variation in the input parameters, there is also variation in the output characteristics

Learn more about why do we get variation?

Definition of Histogram

The pictorial nature of the histogram enables us to see patterns that are difficult to see in a table of numbers.

Key Concept of Histogram

Data always have variation
Variation have pattern
Patterns can be seen easily when summarized pictorially

Example with data

Data Table – Weight of Bars in kg.

Study of Histogram

So, now you draw the graph base on the data you have. But if you dont know how to study it then no use. Therefore here are some points which you should look into it and interpret the data. Refer below points: