Supply in any type of enterprise constitutes a very important and complex part of its operations. In the case of commercial enterprises, it is a fundamental area on which their profitability and functioning depend. It is not just about ordering and purchasing goods. It is a process encompassing many activities, which, as a well-cooperating whole, constitutes an asset of the enterprise. The article presents a concept of commodity supply in an exemplary commercial enterprise. The adopted concept aimed to reduce supply and storage costs and streamline the purchasing process.
The supply optimization concept was developed for a medium-sized commercial enterprise in the general grocery industry – a supermarket. The product offer of the studied enterprise includes over 22,000 different goods. The product assortment, due to the method of delivery, can be divided into two groups: goods delivered by suppliers or manufacturers and goods imported independently by the enterprise. The first group includes everyday consumer goods, such as milk and bread delivered daily, as well as goods for which orders are fulfilled at relatively equal intervals by the manufacturer or intermediary as a result of the distribution of a specific assortment in a given area. The second group consists of goods delivered independently, originating from wholesalers located in close proximity to the studied enterprise. In this case, the order fulfillment time is short and carried out on an ongoing basis. In both the first and second groups of goods, tools can be used that can facilitate decision-making in the area of supply and influence the more effective functioning of the enterprise. However, knowledge about future sales of goods, incurred storage and supply costs, and constantly updated information on the inventory levels of individual goods is necessary. Obtaining this information on an ongoing basis with such a large number of offered goods is possible only with the use of computer technology and appropriate software. The software possessed by the analyzed enterprise allowed for obtaining only part of the necessary information. Therefore, it was necessary to expand the IT system in the enterprise and supplement it with a module allowing for sales forecasting and a purchasing module, integrated with the financial and accounting system and the warehouse system, based on the developed forecast and calculating the optimal order quantity of goods based on an inventory model. The concept of the design of such a system is presented in Figure 1.
The existence of integration between the modules presented in the figure is essential for the proper control of the supply process. The warehouse module provides current information on the inventory levels of individual goods. This currency results from its cooperation with fiscal cash registers and the supply department, from which information about changes in the state of goods in connection with their sale and subsequent deliveries originates. The forecasting module, based on historical sales of goods originating from the database created on an ongoing basis through fiscal cash registers and the warehouse system, generates information about future sales. Due to the ongoing use of information about sales volume, the generated forecast regarding future periods is constantly updated. In this module, an ANN (Artificial Neural Network) was used to develop the forecast. The financial and accounting module in the presented concept constitutes a source of information on incurred supply and storage costs. In the analyzed enterprise, it was modified by supplementing the chart of accounts with additional accounts enabling direct reading of information on supply and storage costs. The essence of the concept is the purchasing module. In this module, based on information about future demand for a given good, originating from the forecasting module that constantly updates the forecast, and current inventory levels originating from the warehouse module, control and analysis of deviations regarding commodity demand are conducted. Information on incurred supply and storage costs is also used. Based on these data, the quantity of ordered goods is determined, ensuring continuity of sales. To calculate the optimal purchase quantity of goods in the purchasing module, two inventory management models were used. One of them is the Silver-Meal model, referring to non-stationary demand. The second one, proposed by the author of the article, is based on the return on invested capital, which is the result of a modification of the Silver-Meal model.
The article comes from the “Logistyka” magazine 1/2009.