The production line is a thing of beauty when it's in full flow. It doesn't matter if the end goal is to make a car or a tin of beans, the process has to work absolutely perfectly for the production flow to reach its optimum potential. Actually, scratch that - there is basically a binary reality of optimum production flow, or zero products being made. If one piece of machinery breaks down, it's normal for the entire production line to come to a standstill.
A good friend of mine is a production line manager for a well known car manufacturer. His job was to ensure the production line was working smoothly. This meant he had to anticipate problems before they occurred. Every single peice of machinery and robotics had a backup very close to the production line. If anything failed, it was swapped out in seconds - not unlike that of Formula 1 mechanics swapping tyres. He was constantly reminded just how much downtime would cost the company. One of his main concerns was that some of the machines themselves were no longer being manufactured - therefore he had to source back-up machines on the second-hand market - even using eBay at times! It surprised me that such a high-tech company would be in such a situation. However he explained that this happened when particular car models were coming to the end of their production lives.
Production lines in the past had their own set of problems - mainly from humans, not machines. The production lines of old featured human labour far more than machinery. That meant line managers had to deal with sickness, varying skill levels, and a sheer lack of concentration from people as the work was so monotonous. No wonder factory owners have favoured machines over people - not just for cost savings, but for accuracy too.
Article kindly provided by JPS Metalworking Machinery