The key points from this module are:

The most common methods of monitoring the quality of products, processes or services are referred to as the collection of statistical tools known as 7 Quality Tools also known as “The Basic 7”. 
The first widespread implementation of these techniques started in Japan popularized by Kaoru Ishikawa, an organizational theorist and professor at University of Tokyo.

Check-sheets
Controlled check-sheets can be expressed in qualitative or quantitative metrics. These are usually in tabular form for reporting, analyzing the real-time data.
Histograms
Histograms are used to represent the frequency distribution of a set of continuous numerical data.