Home > Human Factors history and studies > History of ergnomics – time and motion studies Frank Gilbreth

History of ergnomics – time and motion studies Frank Gilbreth

The today known field of Human Factors Engineering (or sometimes called Ergonomics) has a long history. It started out from efficiency to make tools more suitable for man so that they can work more efficient and productive. The studies used therefor are known as time-and-motion studies. Probably the earliest ones were conducted by Taylor. But Taylor’s was mainly focusing on work rates and worker motivation with the purpose to reduce process time.

The study conducted by Frank B. Gilbreth in 1911 is likely the first one which focused on the relationship between human, environment and tools to make the work more efficient by reducing motions. One of his famous time-and-motion studies concerned brick laying. Beside this he was also known for his systematic management style. For conduction of the motion studies he coded movements and actions of the worker related to work into 18 basic motions (http://en.wikipedia.org/wiki/Therblig) which he called “Therbligs” (Gilbreth spelled backwards). During the conducted motion study the therbligs are written down and analysed for optimisation like unnecessary movements.

In case of the bricklaying study he discovered that the bricklayer needs to bow for each brick and at cases a second time to get a bit water for the brick. Additional effort was it that not each brick could be used. If it was of minor quality the worker would need to throw it and bow again. The study resulted in the invention of a height adjustable scaffold on which the worker arranged a heap of bricks and the mortar. The scaffold could be quickly raised or lowered enabling the bricklayer to work at the most convenient positions and it further enables them to keep up with the height of the wall. By making the motions of handling and inspecting the bricks more efficient Gilbreth enabled bricklayers to increase the number of bricks that they could lay from 120 to 350 per man per hour.

Gilbreth enhanced the method developed by Taylor with what he called micro-motion analysis. Meaning the workers actions are recorded on a video with a chronometer running in the video. Afterwards follows the video analysis with a magnifying glass to discover every motion a worker makes and suggest improvements based on the length and sequence of the motions.

In the studies described were the first ones considering fatigue resulting from a job and the thought that the provision of an adequate work environment and regular breaks forms a more efficient process in the end.

However, the important component of cognition has still to wait until World War 2 until it is considered as important point and integrated into the field of human factors engineering. Cognition came into importance due to growing application of automation and automation specifically taking over the heavy physical work from the operator. What remains for the operator are mainly perception of information and decision-making tasks. Leading questions are e.g.: How much information can be absorbed? How many oxygen masks sizes are required to fit to all men? This was also the point where the field of human factors engineering melted with psychology. Because the questions could no longer be answered by engineers – it needed psychologists, physiologists and physicians.

Sources:

Wikipedia

On the website of the MIT there is a paper: http://web.mit.edu/allanmc/www/TheGilbreths.pdf

Frank B. Gilbreth’s book about bricklaying is free available online: http://web.mit.edu/allanmc/www/TheGilbreths.pdf

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