This blog post highlights some of the differences between quality assurance and quality control, two terms we come across quite often in IT but which also can become murky in their meaning. In short, quality assurance is the overall mindset and processes which promote quality, whereas quality control is a function which is applied to products to attain quality:
Quality Assurance: The function of software quality that assures that the standards, processes, and procedures are appropriate for the project and are correctly implemented. Statistical Tools & Techniques can be applied in both Quality Assurance & Quality Control. When they are applied to processes (process inputs & operational parameters), they are called Statistical Process Control (SPC) & it becomes the part of Quality Assurance.
Quality Control: The function of software quality that checks that the project follows its standards, processes, and procedures, and that the project produces the required internal and external (deliverable) products. When statistical tools & techniques are applied to finished products (process outputs), they are called as Statistical Quality Control (SQC) & comes under Quality Control.
A Useful Table
The blog post then goes on to explain differences between Quality Assurance (QA) and Quality Control (QC), with a list which gives good examples to help show just how the differences can be remembered and evaluated.