پرده برداری از تخفیف کمی

We consider the situation in which a buying organization deals with a discrete quantity discount schedule offered by a selling organization. Furthermore, the buying organization can negotiate with the selling organization about the lot size and purchase price, but does not know the underlying function that was used by the selling organization to determine the quantity discount schedule. In this paper, we provide an analytical and empirical basis for one general quantity discount function (QDF) that can be used to describe the underlying function of almost all different quantity discount types. We first develop such a QDF analytically. Among other things, this QDF enables buying organizations to calculate detailed prices for a large number of quantities. We subsequently show that the QDF fits very well with 66 discount schedules found in practice. We discuss that the QDF and related indicators can be a useful tool in supplier selection and negotiation processes. It can also be used for competitive analyses, multiple sourcing decisions, and allocating savings for purchasing groups. Additionally, the QDF can be included in research models incorporating quantity discounts. We conclude the paper with an outlook on further QDF research regarding the characterization of commodity markets from a demand elasticity point of view.

Quantity discount schedules have been used widely for many centuries [1]. These days, quantity discount schedules come in all shapes and sizes. A typical example of a discount schedule is shown in Table 1[2].This discrete schedule provides the price per item for a limited number of quantities and prices. It does not provide the assumed function which the supplier used to calculate the price per item. Therefore, it is difficult for a buying organization to calculate negotiable prices for the many possible quantities for which no specific prices are provided by the supplier. For instance, if a buying organization needs a quantity of 9500 items, then the question often is what price—in between 40.9 and 45.4—the buying organization can start negotiating with. Another question is whether the buying organization should start negotiations with supplier A (see Table 1) or supplier B (see Table 2) for a quantity of 9500 items.

Previous research on quantity discounts has focused on creating discount schedules and on applying discount schedules in new or existing models. We propose a different perspective. We consider the situation in which a buying organization has to deal with a negotiable discrete quantity discount schedule, but does not know the underlying function that was used by the selling organization to determine the schedule. In this paper, we provide an analytical and empirical basis for one continuous quantity discount function (QDF) that can be used to describe this underlying function. The QDF consists of only three parameters, which can be derived easily from almost all kinds of different types of quantity discounts as mentioned in Section 1.1. In the paper, we show that the QDF fits very well with almost all quantity discount schedule types that we found. The QDF information can be used in supplier selection and negotiation processes. Specific QDF applications range from calculating and allocating savings for purchasing groups to justifying multiple sourcing decisions. In addition, the QDF can be used in research models incorporating quantity discounts. To summarize, we argue that the QDF reduces the price information deficiency for organizations regarding quantity discount schedules provided by suppliers. This reduced information deficiency could lead to lower purchase prices and/or better quality for buying organizations. Still, using the QDF involves some extra operations. Throughout the paper, we argue that these are well worth the effort. For instance, according to Wang [27], a continuous discount schedule could reduce the supplier's discount benefits. In addition, extra information about purchase prices is useful for buying organizations, as prices are often the main basis for purchasing decisions [25]. Finally, our data set shows that quantity discounts can have a major impact on the total purchase costs. We found a maximum discount percent of 90.1 and a mean discount percent of 31.3. The discount schedule behavior of suppliers may differ per market and may also develop during time, following the product life cycle. Further research to QDF indicators and parameters could characterize commodity markets and provide several applications. For instance, for some commodity markets, it could be worthwhile for buying organizations to purchase in groups or to consider a large number of suppliers in selection processes. To be able to utilize such QDF applications, a promising market research line to demand elasticity of price could be set up, following the research line to price elasticity of demand.