Therblig
A therblig is one of 18 kinds of fundamental motions used in the study of motion economy in the workplace. A portmanteau of "Gilbreth" (with the 'g' transposed), it was conceived by industrial psychologists Frank and Lillian Gilbreth as a way to analyze and improve the efficiency of manual work processes. By breaking down tasks into discrete motions, analysts could identify unnecessary movements and optimize workflows.
Each therblig describes a standardized elemental motion, regardless of the industry or task. The 18 therbligs are often categorized into effective therbligs (those that bring the work closer to completion) and ineffective therbligs (those that do not directly advance the work). The goal of motion study is to minimize or eliminate ineffective therbligs while maximizing the efficiency of effective therbligs.
The therbligs include:
-
Search (Sh): An attempt to find an object.
-
Find (F): The point at which the eyes locate an object.
-
Select (St): Choosing one object from a group.
-
Grasp (G): Taking hold of an object.
-
Reach (RE): Moving the hand to an object.
-
Move (M): Moving an object to a location.
-
Hold (H): Retaining an object.
-
Release Load (RL): Letting go of an object.
-
Position (P): Placing an object in a defined location.
-
Pre-position (PP): Positioning an object for a later operation.
-
Inspect (I): Examining an object for quality.
-
Assemble (A): Joining two parts together.
-
Disassemble (DA): Separating two parts.
-
Use (U): Employing a tool for its intended purpose.
-
Unavoidable Delay (UD): Waiting due to factors beyond control.
-
Avoidable Delay (AD): Waiting that the worker can control.
-
Plan (Pn): Deciding on a course of action.
-
Rest (R): Taking a break to overcome fatigue.
Therbligs are a foundational concept in time and motion studies and continue to be relevant in contemporary ergonomics and process improvement methodologies. They are used to increase productivity, reduce worker fatigue, and improve overall efficiency in various industries.