A key character of scheduling is the productivity, the relation between quantity of inputs and quantity of output. Key concepts here are:
- Inputs : Inputs are plant, labor, materials, tooling, energy and a clean environment.
- Outputs : Outputs are the products produced in factories either for other factories or for the end buyer. The extent to which any one product is produced within any one factory is governed by transaction cost.
- Output within the factory : The output of any one work area within the factory is an input to the next work area in that factory according to the manufacturing process. For example, the output of cutting is an input to the bending room.
- Output for the next factory : By way of example, the output of a paper mill is an input to a print factory. The output of a petrochemicals plant is an input to an asphalt plant, a cosmetics factory and a plastics factory.
- Output for the end buyer : Factory output goes to the consumer via a service business such as a retailer or an asphalt paving company.
- Resource allocation : Resource allocation is assigning inputs to produce output. The aim is to maximize output with given inputs or to minimize quantity of inputs to produce required output.