The field of Ergonomics has a long history. Some of its origin can be found in the need to create an efficiently running business during the age of industrialization. Old studies, called time-and-motion studies, aimed to optimize manual workforce.
Probably the first studies were conducted by Taylor around 1900. Taylor focused on an improvement of work rates (measured by a stopwatch) and processes to increase productivity. He often compared different ways to do a task and different tools to do a task to identify the most efficient one. For example, in one study he measured how long a worker needed to shovel coal. The result was that a worker could shovel 21 pounds without tiring. However, at that time each worker was required to bring their own shovel. To increase productivity Taylor provided his workers with shovels and even provided different shovels for different densities of material (for example, 21 pounds of snow is a larger heap compared to 21 pounds of coal).
Taylor’s work is criticized for missing individual differences in work capability giving workers freedom to innovate, but instead aiming for a standardization of the work process and for a maximum efficiency. Taylor is said to believe in the optimization of the work process rather than focusing on individual workers. His work can be seen as a first step towards standardization of the work processes. Others, such as the Gilbreths, focused more on the workers’ wellbeing.
Frank B. and Lillian Gilbreth, associates of Taylor, took those task analyses one step further and took photos of each individual movement while conducting a task in 1911. The studies were called time-and-motion studies and included a micro-motion analysis. The workers’ actions were recorded on video with a chronometer running in the video. Afterwards, the video was analysed with a magnifying glass to discover every motion of a worker Then each movement that a worker made was coded into 18 basic motions (http://en.wikipedia.org/wiki/Therblig) called “Therbligs” (Gilbreth spelled backwards). The therbligs were analysed for optimizations like unnecessary motions, and optimizations of the length and sequence of motions.
For example, one time-and-motion study concerned bricklaying. The Gilbreths discovered that a bricklayer needed to bow for each brick. After a few bricks an additional bow was required to add new mortar. When the bricklayer discovered a brick of minor quality, additional motions were needed. The minor quality brick was thrown and the bricklayer needed to bow again to pick another one. The study led to the invention of a height adjustable scaffold on which a heap of bricks and the mortar were arranged. The scaffold could be raised or lowered quickly enabling the bricklayer to work at the most convenient positions and it further enabled 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.
The Gilbreths were the first to set the focus on the relationship between human, environment and tools. They described fatigue that results 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. Today time and motion studies are still used, for example, in health care to analyse the work of nurses to optimise a shift schedule. I will describe their procedure in another post.Sources:
Lumen (2019), Principles of management. (online) https://courses.lumenlearning.com/principlesmanagement/chapter/3-2-ancient-history-management-through-the-1990s/
Wikipedia (2019), Therblig. (online) http://en.wikipedia.org/wiki/Therblig
Content for Pragyan (2017), Time & Motion Study – Making the most of our time. (online) https://medium.com/pragyan-blog/time-and-motion-study-ed7b6979ebfc
M. Lopetegui, P-Y. Yen, A. Lai, J. Jeffries, P. Embi, and P. Payne (2014). Time motion studies in healthcare: What are we talking about? Journal of Biomedical Informatics, 49(2014), 292-299.
A. Hendrich, M. Chow, B., Skierczynski, and Z., Lu (2008). A 36-Hospital Time and Motion Study: How Do Medical-Surgical Nurses Spend Their Time? The Permanente Journal, 12(3), 25-34.