Optimised Production Technology (OPT) is based on the philosophical approach that the primary goal of any business is to make money. In order to achieve the primary goal, certain rules are to be followed. In the manufacturing process area, the criteria used to evaluate the progress of OPT towards the ultimate goal are defined as:

• Throughput;
• Inventory; and
• Operating expenses

In the OPT context, “throughput” is defined as the rate at which finished goods are sold, rather than the rate of production. “Inventory” is considered to include everything from raw material to fully finished goods (unsold). “Operating expenses” include the cost of labour, and all other input costs (such as power). In the OPT context, the goal of manufacturing involves increasing the level of throughput, with a simultaneous decrease in inventory and operating expenses.