This textbook is the further and new development of the two books "Kostenrechnung für Ingenieure" and "Wirtschaftlichkeitsrechnung für Ingenieure", both previously published by Hanser, in one volume. The topics of cost accounting and cost management are of particular relevance to engineers, as they determine essential cost dimensions of products in research and development as well as in design. A sound understanding of the origin and influenceability of costs is therefore indispensable to ensure the market success of products designed by engineers. In addition to the basics of cost accounting, the book therefore contains in particular the knowledge about the management of costs, i.e. about the recording and distribution of costs to the products as well as the early influencing of costs in the context of the creation of new products. Especially in this development process i.