The terms standard operating procedure or SOP, is used in a variety of different contexts, such as healthcare, education, industry or the military.
Clinical research
In clinical research, the International Conference on Harmonisation (ICH) defines SOPs as "detailed, written instructions to achieve uniformity of the performance of a specific function".
Business and manufacturing practice
An SOP is a written document or instruction detailing all steps and activities of a process or procedure. ISO 9001 essentially requires the documentation of all procedures used in any manufacturing process that could affect the quality of the product.