A Century of Flowcharts

History of a design artifact

As interaction designers, much of our daily basis work is to document graphically conceptual aspects as processes and features, descriptions of models that can affect both the software or the service that we are designing. One of the most popular models are the flowcharts: an artifact that describes visually and sequentially the instructions of a process.

Its history dates back to the early twentieth century, more or less between 1908 and 1924, when Frank and Lillian Gilbreth systematically studied the movements being made by workers in order to improve their tasks. They documented this study, through movies and 3D models of the user’s movements.

To project graphically this systematic research, they created a visual alphabet called “Therbligs” (Gilbreth read upside down), giving a name to each one of the actions involved in a task.

Therbligs signs

By diagramming the therbligs sequentially, they could identify unnecessary or inefficient tasks, even eliminating fractions of a second in lost time, creating this way the first approach to graphical processes.

Frank Gilbreth introduced the first flowchart to ASME members in 1921. In his presentation “Process Charts — First Steps in Finding the One Best Way”, as a result of joint research with his wife, he already emphasized the synthetic and iterative purpose of the device:

The Process Chart is a device for visualising a process as a means of improving it. Every detail of a process is more or less affected by every other detail; therefore the entire process must be presented in such form that it can be visualised all at once before any changes are made in any of its subdivisions. In any subdivision of the process under examination, any changes made without due consideration of all the decisions and all the motions that precede and follow that subdivision will often be found unsuited to the ultimate plan of operation.

The intention of the Gilbreths was to represent graphically, in a synthetic and abstract way, the current conditions of a process, in order to optimize it and make it more profitable and efficient. By diagramming a process, was easier to detect an error and possible inconsistencies, as we have an overview of the entire system.

Process chart for loading riffle grenades by the Gilbreths

They soon concluded that it was also an effective way of presenting an idea from other perspectives, from the point of view of the business or the service, as it was a very structured display.

In the early 30s, Allan H. Mogensen, an industrial engineer who had studied the Gilbreth’s methods, after performing consulting work for companies such as Kodak, joined Lillian Gilbreth & Associates team, where he begin to train business people in the methods of work simplification through process modeling.

The use of flowcharts, was a good tool to mediate between different departments and stakeholders, helping to solve communication problems and ironing out possible discrepancies. It also allowed to identify patterns and similarities between processes, enabling a more efficient use of tasks and facilitating the transfer of skills.

Mogensen and Graham

Mogensen trained many people in the “Work Simplification Conferences”, an intensive six-week program that took place in Lake Placid (New York). Since 1937, this program influenced for almost 50 year professionals as Art Spinanger and Ben S. Graham, who helped to save billions of dollars in companies like Procter & Gamble. Later on, Graham also contributed to take further the original diagram presented at Mogensen conferences, expanding it to multiple streams of information.

A few years later, in the fervor years of Scientific Management, the ASME adopted a set of 5 symbols in 1947, derived from the original work of the Gilbreths, as the standard for process diagrams flows. The same year Herman Goldstine and John von Neumann created the current visual alphabet of flowcharts for computer engineering, which corresponds to the basic functions or instructions of a computer, thus facilitating the subsequent translation into a programming language.

Flowcharts symbols
  • Termination (oval rectangle), where it starts or ends the diagram.
  • Process (rectangle), that shows the calculations.
  • Decision (diamond), indicates a situation of true or false.
  • Input / output, indicates read and write functions.

At Interaction Design discipline are often used the latter ones, in a more or less sophisticated version depending on the context, and in a more flexible way by combining them with other graphic elements.

It is surprising that, despite being a device used in a multitude of disciplines and methodologies of innovation, it is a tool with over 100 years of diagrammed history.



This Article was originally written in Spanish at Guindo’s blog:
100 años de diagramas de flujo

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