The goal of quality and reliability assurance (QA) is the continuous improvement of reliability, performance, efficiency, and ease-of-use of a product or service in order to render it more cost-effective and beneficial for the customer or user. A key part of QA is quality control (QC) – the acquisition and analysis of quantitative observations made during the process of production for a product or of implementation for a service. QC allows a process to be continuously monitored and maintained to meet the desired specifications (stable process in statistical control) or ultimately rapidly diagnosed and remedied if problems arise and the results deviate from those expected.
Each production process and product has its own unique attributes and may require specific methods of observation for the carrying out of QC. Generally, the production of electronic, microelectronic, and mechanical devices, as well as materials and compounds, require QC measurements using a technique involving microscopic analysis, often optical microscopy.