Erply keeps track of your inventory: quantity of each product in each warehouse (also known as a store, or a location). Inventory is managed according to "First In, First Out" (FIFO) principle. It means that Erply knows what batches of inventory are currently in stock, and when items are sold, they are taken from the oldest batch. This is how the cost of the sold items is determined.
However, users cannot pick a specific batch to sell from, and the batches are not exposed through reporting. Therefore, Erply might not suit for managing perishable goods (where batches have an expiry date).
A batch gets created when you take items into stock. Items can be taken into stock:
A batch has a purchase price and a cost. Cost equals purchase price plus additional costs (eg. freight and duties — this value can be specified when creating a purchase invoice). When items are taken into stock with an Inventory Registration, purchase price and cost are equal. Inventory and COGS (Cost of Goods Sold) show inventory value both in purchase prices and in unit costs.