Some tools/techniques that can be used to assess quality assurance include:

Fishbone Diagram. In this cause-and-effect type diagram factors causing a defect are listed as inputs and their combined efforts may output the possible defect. For example, inputs such as suspicious, unchecked glue suppliers, high humidity in the factory, and an untrained workforce may output poorly sticking labels. This output would require a change request in the supplier and/or better air quality and/or a training program to improve the quality of the product’s label adhesion.

Cost of Quality (COQ). In this hierarchical chart outputs are quantified and assessed on the basis of the quality of their inputs; meaning, how to best utilize our resources to prevent poor product quality while keeping costs as low as possible? Would hiring a large workforce possible prevent defects (and associated costs) from arising? Would running an audit on your supplier result in a better inspection check? Are these improvements worth paying for?

The results of these quality assurance processes help ensure that the final product is at optimum quality level.