This book describes the design of a performance-based cost accounting system for hospitals that can be implemented on a personal computer. An important topic is cost and performance accounting as a subfield of management accounting from business administration. Here, not only are the relevant terms for this book explained, but also how the creation of services can be broken down into types of services and service areas (so-called decomposition in the sense of a "top-down" approach). Another central theme is software engineering with its phase-oriented approach from computer science. The described system design is illustrated using the example of service provision in a hospital. In principle, the approach and the considerations described can easily be transferred to other companies as well.