Abstract
The type series is a set of product sizes to be produced in large quantities in order to satisfy the existing demand. The paper is concerned with optimizing the type series with respect to the economical effect it induces in manufacturing and use of the product. A general mathematical model is presented which establishes logical links between the design of a single product size and the design of the entire series. The principles of evaluation and the concept of optimality of the type series are discussed and illustrated by two examples.