Adding on to this, here are some more quality assurance tools and techniques:

Pareto chart: This is a bar graph where length represents frequency (e.g. of complaints) or cost, and where the bars are arranged left to right in order of longest bar to shortest bar. Here the most significant matters to address are located on the left. These help when there are a multitude of problems to address and you only have the resources to focus on the most significant ones.

Control chart: Basically a standard line chart where data is plotted over time and compared to an average. This can be handy in observing an outcome as a project progresses, seeing if a process is stable, and projecting outcomes in the future. The average may be previously acquired historical data or it could be a minimum goal to be met.