EN
Product modification and shaping production assortment are a basic element of a company’s marketing strategy. The article emphasizes the necessity of promoting the policy o f product differentiation by a company. It consists of two parts. The first part deals with shaping the assortment of products, as today most firms manipulate a multitude of products and an appropriate determination of width and depth of assortment decides about a firm’s success on the market. The article analyzes also the relationship between the shaping of assortment and life cycle of products, because depending on the stage in product life cycle a company should introduce changes in its policy. The second part of the article deals with modification of products. There are discussed here three main strategies in product differentiation: strategies of upgrading the qualify, characteristics, and appearance of a product. A short mention is also made of the problem of abandoning weak products and replacing them by new ones.