The fundamental flaws of the paper which led to the incorrect conclusion were unreasonable sampling method for determining As concentration at various water depth and the wrong lake water volume of 6.04×108 m3 (actually 4.8×108 m3) for calculating inventory of As in Yangzhonghai in August 2012.
Firstly to calculate inventory turnover we need Cost of Goods sold and closing stock from the trading profit and loss account as inventory ratio means at what rate the stock of finished goods or materials are converted into sales or finished goods respectively.
The profit was calculated with inventory valued at its replacement cost.
Furthermore, they calculated an inventory time reduction of 8% to 17% when a two-tag detection and collision recovery is utilized.
Remember that even though this number will always be lower than the Current Ratio, it doesn't mean the company is doing worse, because you're comparing this company's Quick Ratio to the industry average Quick Ratio, and every other company's number will have been calculated without inventory as well.
Calculate the inventory days using the following formula: Inventory Days = 365 x (Average Inventory / Cost of Goods Sold).
The transportation cost depended on the locations of suppliers, and finally average inventory level in each period is used to calculate the inventory cost for buyer.
For supplies that may expire or become obsolete, calculate the inventory turnover (cost of goods sold divided by inventory) and make sure the time to expiration/obsolescence is well below the period of time implied by the turnover.
For this reason, an (R, Q) inventory model has been developed, and to prepare a cohesive model, demand and lead time have been considered as stochastic parameters, and queuing theory has been used to calculate average inventory costs.
However, for conversion systems which are more spatially diffuse (e.g., biogas) and have a greater number of bioenergy plants scattered across the region, it would be time intensive to calculate an inventory assessment for each of these bioenergy configuration.
