2. implementation and control. these are responsible for putting into action and achieving the plans made by production planning. these responsibilities are accomplished through production activity control (often called shop floor control) and purchasing.
3. inventory management. inventories are materials and supplies carried on hand either for sale or to provide material or supplies to the production process. they are part of the planning process and provide a buffer against the differences in demand rates and production rates.
production planning, implementation, control, and inventory management work together.
inventories in manufacturing are used to support production or are the result of production. only if items are purchased and resold without further processing can inventory management operate separately from production planning and control.
even then, it cannot operate apart from purchasing.