Quality in the industrial or service context is an attribute of a product or service. For easier reading we will write "product" but mean "product or service".
A pragmatical definition is "fit for use". This means, the product will meet your expectations and you can use it within the intended purpose.
Quality control (QC) is the process where products (and services) are checked if they fit to the expectations of consumers.
Quality function deployment (QFD) is a method to
- transform user demands into design quality,
- to deploy the functions forming quality, and
- to deploy methods for achieving the design quality into subsystems and component parts, and
- ultimately to specific elements of the manufacturing process.
QFD was developed in Japan in 1966 by Dr. Yoji Akao.
The term quality management has a specific meaning within many business sectors. This specific definition, which does not aim to assure 'good quality' by the more general definition, but rather to ensure that an organization or product is consistent, can be considered to have four main components: quality planning, quality control, quality assurance and quality improvement (Or shorter: PDCA Plan, Do, Check, Action) .