They are known since heyday of Total Quality Management in the 1970s and they are still used and useful today: the seven quality control tools.
These tools have been selected to give shopfloor workers means to control, analyse and improve quality based on facts and objective data. The tools are simple enough to be used with minimum algebra.
The seven quality control tools are:
- Check Sheets
- Pareto Chart
- Cause & Effect diagram
- Scatter Diagram
- Control Chart
Their order may vary from one author to another but order is not that important.
Here is a 8mn video listing the 7 quality control tools provided by Gemba academy