Assembly line worker — tasks, one by one

Repetitive assembly at a fixed station

Fixed automation and industrial robots have been replacing this task for fifty years wherever volumes are high and parts are consistent, and collaborative robots have lowered the volume threshold at which it pays. The remaining human stations are the ones where parts vary, volumes are low or the product changes too often to justify tooling.

Automation decisions here are driven by labour cost relative to capital cost, which is why the same product is assembled by robots in one country and by people in another. Wages, not capability, set the pace in most of the world.

Dexterous or variable assembly

Cables, gaskets, fabrics and anything that deforms remain hard for robots, and mixed-model lines that change every few units defeat fixed tooling. These stations are where people have stayed even in heavily automated plants, and they are a large share of final assembly in electronics and vehicles.

These stations survived in heavily automated plants, which means they survived as a small remainder inside a plant that already shed most of its line jobs. Surviving the last round is not the same as being safe.

Inspection and quality checks

Machine vision inspection is mature, cheaper than a person and does not get tired at hour seven, and it has displaced visual inspection stations in most modern plants. What remains for people is the judgement on borderline cases and on defects the system was not trained to see.

Machine vision displaced visual inspection stations in most modern plants. What remains is borderline cases and untrained defect types, which is a fraction of the shifts inspection used to fill.

Tending machines and running changeovers

As stations automate, the operator's job shifts to keeping the automated cell running: a few people tend several machines. The work is less repetitive and more diagnostic, and it is the form the assembly job increasingly takes rather than disappearing outright.

A few people tending several machines is the whole point: the ratio is the saving. This task describes the form the job takes on the way down, not a stable destination.

Programming and maintaining the robots

Every automated line needs technicians who understand both the product and the equipment, and plants consistently report shortages of them. Robot programming has become far easier — teaching by demonstration rather than code — which opens these roles to experienced operators rather than only engineers.

Plants report shortages of these technicians while also not funding the training that would produce them from the operators they already have. The opening is real and the bridge to it is not built.