Inventory

1. In the USA, the equivalent of the UK *stock, i.e. the products or sup­ plies of an organization on hand or in transit at any time. For a manufacturing company, the types of inventory are raw materials. Work in progress, and finished goods. An inventory count usually takes place at the end of the *financial year to confirm that the actual quantities sup­ port the figures in the *books of account. The differences between the inventories at the beginning and the end of a period are used to calculate *cost of sales for the *profit and loss account, and the ending inventory is shown on the *balance sheet as *circulating cap­ital.

2. More broadly, the total accumula­tion of material resources within an *operating system (not only what is held deliberately in stock). It includes all the transformed resources locked up in the system, such as work in progress. Scrap. Rejects. etc. All operations have some inventory, which represents locked­ up capital. The task of *operations is to ensure that levels are kept to the mini­ mum without affecting the efficiency and effectiveness of the transformation process. Inventory, in this sense, falls into several different categories. Anticipatory inventory is produced in periods of relatively low demand in antic­ipation of a later increase in demand. This is only possible if the goods are non-perishable and are only economically viable if the storage costs are less than the costs of changing production levels to match demand. Uncoupling inventory is the amount of material held to decou­ple elements of the *transformation sys­tem, JiUCh as the raw-material supplier from·the manufacturer, one machine from another, or the manufacturer the customer. This provides an element of operational flexibility. Similar to uncoupling inventory is the buffer inventory, which protects against varia­tions in supply, demand. And lead times. It represents a safety margin and is therefore directly related to the reliabil­ity of demand forecasting. Etc. Pipeline inventory is that part of the inventory that is locked up in the system. Because all processes take time, the pipeline is a function of a *transformation system rather than performing a function within it. If organizations have to sub­ contract part of their products or if ele­ments of the system are widely separated geographically, the number of resources locked up in the pipeline can increase dramatically. Modern process-monitoring systems based on *information technol­ogy are designed to ensure that the pipeline inventory, in particular, is kept to a minimum. Cycle inventory is a func­tion of the *economic order quantity (ECQ) calculation and represents a trade­ off between minimizing the inventory and the costs of setting up and changing processes. Just-in-time techniques are designed to rely on a minimum ECQ. There is some overlap between these different types of inventory.