Assembly lines: history, present, and future

21 Feb 2023

Automobiles have become an integral part of our lives, and the simplification of the assembly process plays a big part in the constantly increasing demand.

Only 100 years ago, every car part was assembled manually, which significantly impacted assembly times and increased the final cost. Today, the automotive industry is one of the most automated and produces dozens of thousands of various models per day.

Automotive plants have evolved from dirty warehouses full of tired workers to elegant and futuristic assembly lines that offer more precision than human labor. Plus, the constant arms race for improving production quality between the manufacturing giants makes them invent new automation methods almost every day.

Henry Ford, the inventor of the first mass-production assembly line

In 1911, Henry Ford came up with the idea of a moving conveyor belt where the workers assemble the car by placing the parts in a strict order, one after the other. This concept, in turn, allowed for standardizing some details and components, making them mutually replaceable, and creating the first production chains. As a result, it allowed Ford to achieve a few things:

  • decrease the final care price to $260;
  • increase the production rates: by 1914, Ford plants manufactured 10 million of automobiles (10% of the world’s cars);
  • pay the workers the highest regional wage: $5/day.

Ford wasn’t the first person who invented a conveyor belt, but he paved the way for workshop automation back in the day.

The level of assembly line automation increased along with breakthroughs in electronics and computer technologies. Plants operated on mechanical assembly lines until the 1930s when Japan improved the production process by introducing electronics, which gave the plants a major advantage over the competitors.

The findings of Japanese engineers allowed for establishing of high-quality standards, which the country is famous for today. In 1960, Mazda created the first car with a rotor engine, which earned the company a reputation as a “fast cars manufacturer”.

Honda concern, founded by Soichiro Honda in 1948,  become the first car seller known around the world. Its cars were featured in rallies and competitions, from regional to worldwide.

George Devol and his Unimate, the first industrial robot used at General Motors automotive plants and assembly lines

The turning point for the automotive industry was the first production robot, Unimate, created by George Devol and patented for mass production in 1961. Only a year after, General Motors started using Unimate for technological processes at one of their plants, which made the plants gradually switch towards full automation.

Today, machines have replaced humans in the most dangerous links of the production chain, which helped to decrease the chances of accidents and risks connected to the human factor. However, modern assembly lines still cannot be 100% automated and require a person to control and operate them. First, the upgraded equipment requires operators skilled in programming, robotics, and automation. Second, processes like quality control, packaging, and dispatching require someone to control each step, and the machinery isn’t capable of doing that yet.

Having robots and machines integrated into the production process allowed to increase manufacturing capacities and improve the quality of the final product. Starting in 1980, Ford began to  equip its plants with resistance spot welding robots. Ford Fiesta become the first car where the anti-corrosive hermetic was sprinkled by robots directly in the frame.

The impact of using electronics during the assembly process is hard to define. Even though machines replaced a lot of manual labor, they gave birth to a host of new professions that require skilled workers. This allowed to bring the automotive industry to a whole new level, minimizing the number of errors and scaling up mass production. As a result, the max threshold for wear-and-tear for modern cars is around 500,00km, compared to 250,000km , which was only a few decades ago.

An example of an assembly line machinery: a welding robot

Describing the machines that make up the assembly line will take some time, but we’ll briefly go through the main ones:

  • Mounting machinery. Its primary purpose is placing the parts and components on the car frame. The newest generations of mounting robots can also install tires and tighten all the screws and nuts at once.
  • Spot welding and arc welding robots. They work on the assembly of the car body. The average welding robot looks like a machine with dozens of hand manipulators that perform welding at several points at the same time.
  • Robot painters. They not only apply different coatings but also seal the joints, making the car look glossy and shiny.
  • Assembly robots. They retrieve the final components and transfer them to other workstations. Assembly robots are often used in molding and casting zones, where temperatures can reach up to 1000C and pose a threat to workers.
  • Logistic systems and material control. These small robots move the components between different workstations and collect data about raw materials in the warehouse. Based on the obtained data, the system creates a report about the number of details needed to support an uninterrupted production process.

All systems work in synergy, therefore ensuring a constant increase of efficiency and allowing to produce more cars in a shorter amount of time. Plus, they reduce the level of work-related accidents and create a safer work environment.

However, some processes still require human labor. For example, engine assembly is a complex process and is still done manually by a team of workers equipped with tools.

The development of newer automotive production methods always went hand-in-hand with the technological revolution. Today we can see how the latest scientific discoveries and inventions influence the automotive industry and open new perspectives.

For example, the WIRED recent article explores the use of artificial intelligence and 3D printing on Ford’s  assembly lines, which helps to increase production speed. Another very popular idea is to transition fully to electric vehicles and discard IC engines and fuel in favor of green energy alternatives.

No one knows how our future will turn out, but we can surely say that people won’t stop using cars as a means of transportation for decades. This means that the demand for high-precision machinery will increase and inspire engineers to invent new ways to optimize production.