An assembly line is a production methodology that breaks a process down into discrete steps that are executed in an iterative manner. Assembly line production has its roots in manufacturing and is often associated with Henry Ford and the mass production of automobiles.
Ford’s inspiration for moving to a continuous-flow production methodology likely came from several food-related industries, but is often credited to his observation of how disassembly lines were used in the meatpacking industry at the turn of last century. Ford observed that workers in meat plants remained in a stationary position performing the same small task over and over, while the product – in this case, an animal carcass – did the moving. Because workers were only responsible for one small task, plant managers could hire unskilled workers and when necessary, replace them quite easily.
As a result of what he learned, Henry Ford and his managers changed how Ford automobiles were manufactured and used four guiding principles to reduce manufacturing costs:
- Create a division of labor
- Reduce wasted effort
- Use interchangeable parts
- Manufacture in a continuous flow
In 1908, the Ford Motor Company introduced the moving assembly line and successfully reduced production time for a single car from over 12 hours to just 93 minutes. The change in manufacturing also process significantly decreased the assembly time per vehicle and increased the profit margin for each car.
Ford's manufacturing principles have been adopted by countless other industries. Today, assembly lines are common methods of assembling complex items such as transportation equipment, household appliances and electronic goods. Assembly lines and the manufacturing industry continue to evolve with technological innovations like labor automation, 3-D printing and machine learning.