There are two types of inventory management systems: Dependent demand, which often involves materials and components, and independent demand, which tends to focus on finished products. They are partitioned into the respective classes of Just In Time manufacturing (JIT), the MRP system, and a JIT-MRP hybrid system. Expansions on these systems follow.
Dependent demand systems revolve around goods that aren't in demand on their own and are dependent on the production of a separate item. Raw materials and product components are a great example of dependent demand items, as the demand for them is dependent on the demand for a finished product.
The subdivisions of the dependent demand system are Just In Time manufacturing (JIT), the MRP system, and a hybrid of both. JIT systems focus on producing the right items in the right place at the right time so as to lessen, if not eliminate, manufacturing wastes. MRP systems are prediction-based and help with planning and determining timelines and supply needs, which adds an element of control to all production phases. Finally, the hybrid system combines the JIT system's efficiency with the more analytical methods of the MRP system.
The independent demand system of inventory management is applied to finished products and other goods where the demand for one item does not relate directly to the demand for another. So while automobile parts and accessories are managed based on a dependent demand system, the completed automobile is managed through an independent demand system.
The subdivisions of independent demand inventory management are the fixed order quantity and fixed time period systems, and they're pretty straightforward. The fixed order quantity model functions through a constant monitoring system, wherein a fixed amount of stock is purchased whenever a given inventory level reaches a predetermined point. Thus, order quantities are static. On the other hand, the fixed time period system operates through a series of reviews conducted at regular, fixed intervals. Order quantities are not static in this case; rather, they are based on the difference between current inventory and a predetermined level.
There's more to it than the above - inventory is a complicated subject - but this information should be a good start.
Dependent demand systems revolve around goods that aren't in demand on their own and are dependent on the production of a separate item. Raw materials and product components are a great example of dependent demand items, as the demand for them is dependent on the demand for a finished product.
The subdivisions of the dependent demand system are Just In Time manufacturing (JIT), the MRP system, and a hybrid of both. JIT systems focus on producing the right items in the right place at the right time so as to lessen, if not eliminate, manufacturing wastes. MRP systems are prediction-based and help with planning and determining timelines and supply needs, which adds an element of control to all production phases. Finally, the hybrid system combines the JIT system's efficiency with the more analytical methods of the MRP system.
The independent demand system of inventory management is applied to finished products and other goods where the demand for one item does not relate directly to the demand for another. So while automobile parts and accessories are managed based on a dependent demand system, the completed automobile is managed through an independent demand system.
The subdivisions of independent demand inventory management are the fixed order quantity and fixed time period systems, and they're pretty straightforward. The fixed order quantity model functions through a constant monitoring system, wherein a fixed amount of stock is purchased whenever a given inventory level reaches a predetermined point. Thus, order quantities are static. On the other hand, the fixed time period system operates through a series of reviews conducted at regular, fixed intervals. Order quantities are not static in this case; rather, they are based on the difference between current inventory and a predetermined level.
There's more to it than the above - inventory is a complicated subject - but this information should be a good start.
