Autolite copper core spark plugs use a copper-glass seal that bonds the insulator and terminal post center electrode together.
Overproduction or overstocking leads to increased inventory and money sitting idle. Inventory means any goods that are being held for any length of time, inside or outside the factory. In the Lean system, inventory is regarded as a symptom of a sick factory.
The factory system is a method of manufacturing using machinery and division of labour. Because of the high capital cost of machinery and factory buildings, factories are typically owned by capitalists who employ the operative labour.