مقاله سال ۲۰۱۶

 مجله امگا – Omega

Internal resource waste (IRW) in a production or service system refers to the waste of intermediate resources that is caused by imbalances between the initial and final stages in internal processes. IRW can be an outcome of a number of factors, including asymmetric information, inconsistent production pace, imperfect quality management, and uncertain inbound logistics processes. It occurs when the intermediate products produced by a stage in a process exceed the needs of the next stage. Most of these over-supplied products become waste and are typically stored in the warehouses of either the buyer or the vender, sold to others at a relatively low price, or even disposed of. Thus, it is necessary to investigate the IRW for realizing waste reduction which is one of the primary long-term goals of organizations [1].

A good example of internal resource waste reduction can be seen in the case of the famous Japanese company, Toyota Motor Corporation. After World War II, Toyota experienced a severe shortage of materials, and could not afford the high level of waste that was characteristic of most American companies at that time, in areas such as labor, inventory, space, and processing. Therefore, Toyota created a production mode that it named the Toyota Production System (TPS), which is driven by orders and demand, allowing it to produce only the necessary products within the required time. The physical flow of Toyota’s production system is shown as follows. Parts are produced by suppliers and transported to factories based on inbound logistics. Factories use the parts to produce vehicles. Finally, the vehicles are sent to dealers based on outbound logistics. We define the processes moving from suppliers to factories as part of the production stage and the processes moving from factories to dealers as part of the sale stage.

Toyota made a great effort to reduce internal resource waste between two nearby stages. For example, the company tried its best to realize a goal of “zero inventory” in factories by ensuring that they produced only the necessary vehicles to meet customer orders in the sales stage. Because of its ability to reduce internal resource waste, Toyota underwent rapid development and became one of the most competitive motor makers in the world. And in 2012, it was ranked first in the world in automobile sales [2].