Abstract
Developing a product configuration system is a non-trivial and challenging task for various reasons. First, the domain knowledge which has to be encoded into the system is often spread over several departments or functions within a company. Beside that, in many cases data from existing information systems have to be integrated into the configurator. Finally, the business rules or technical constraints which define the space of possible configurations can be relatively complex and also subject to frequent changes. This makes acquiring and encoding domain knowledge as well as testing and debugging particularly demanding tasks. In this chapter, we give an overview of the challenges when developing a knowledge based configuration system. We will particularly focus on questions related to the knowledge acquisition process and will additionally show how model-based debugging techniques can be applied to support the knowledge engineer in the testing and debugging process.