This week's topic is: Quality Assurance vs. Quality Control: 5 Differences
change control (n.) - a process—either formal or informal—used to ensure that changes to a product or system are introduced in a controlled and coordinated manner. It reduces the possibility that unnecessary changes will be introduced to a system without forethought, introducing faults into the system or undoing changes made by other users of software.
efficacy (n.) – synonym of effective / in pharmacology a distinction is made between both words. efficacy is how well a vaccine works in a controlled environment (lab), whereas effectiveness refers to the real world.