The assembly process involves an arrangement in which component parts are assembled in a step-wise fashion to create a finished product. The completed assembled item may be created by one individual person, or multiple individuals who contribute one or more steps to the assembly process. If each worker is completing one part of the manufacturing process repetitively, and moving the partially assembled item forward to the next worker in line, this is called an assembly line.
Assembly work is often associated with factories, which are organized systems housed within locations designed for mass-producing products. Henry Ford is credited as the originator of the assembly line in the early part of the 20th century. Abundant archeological evidence indicates that the assembly line process was used in a more primitive fashion thousands of years ago in building and constructing ancient artifacts and buildings.
An impediment to efficient assembly is bottlenecks in production lines. Bottlenecks are caused by those parts of the assembly process requiring the most time to complete. Synchronous manufacturing overcomes bottlenecks in the assembly process by synchronizing the overall work flow to match the time requirements of bottleneck processes.
Assembly processes may be highly customized or uniform. If the former case, this is considered handcrafting, and it is typically used in manufacturing items like high-end furniture, or the crafting of fine musical instruments. Individual items also may be tailored specifically to a particular customer's order. This is referred to as custom assembly.
In search of ever more efficient assembly techniques, innovations continue, with modern developments including lean manufacturing and robotic assembly. Robotic assembly has many advantages that include consistent, 24-hour assembly-line performance without interruption or exhaustion. The first working robot in the U.S. made its debut in 1961 at a General Motors plant. The robotic industry has made significant inroads into the assembly process since then.
Lean manufacturing has transformed the assembly process. In highly developed nations that have invested heavily in manufacturing industries like automobile production, lean assembly applies lean practices to the assembly-line workflow. These practices include optimally organizing both people and machines, ensuring all equipment and tools are optimized and in the right place, and having consistent work stations that allow for interchanging personnel, when necessary.
At the other end of the spectrum, assembly work in some countries has been associated with high rates of suicide due to poor working conditions. Long hours and a military-style work culture imposed on employees create an atmosphere of despondency. Assembly workers, historically, have attempted to organize into unions to ensure adequate compensation and safe working conditions.