Which term describes an established way of performing a task?

The term that describes an established way of performing a task is "Procedure." A procedure outlines a specific set of steps or instructions designed to accomplish a certain goal or achieve a consistent outcome. In many contexts, procedures are developed through careful planning and are intended to be followed closely to ensure safety, efficiency, and effectiveness in carrying out a task.

While "method" could also imply a systematic way of doing something, it is often broader and can encompass different procedures. "Technique" generally refers to a specific skill or the manner in which a task is performed, but it doesn't necessarily convey the structured, step-by-step nature of a procedure. "Strategy" typically indicates a plan designed to achieve a longer-term goal and may not involve a fixed set of steps, focusing instead on the overall approach or direction rather than the detailed process.