Abstract. As products are growing more complex, so is their documentation. With an increasing number of product options, the diversity in service and maintenance procedures grows accordingly. This also holds for large-scale medical devices like Magnetic Resonance (MR) Tomographs. Siemens Medical Solutions has thus decided against one common on-line service handbook for all its MR Tomographs. Instead, they fragment the on-line documentation into small packages, out of which a suitable subset is selected for each individual product instance. Selection of (so-called) help packages is controlled by XML terms encoding Boolean choice conditions. To assure that the set of available help packages is sufficient for all valid product instances, we developed a tool called HelpChecker that provides a transformation of XML terms to propositional logic formulae, and then employs BDD-based methods to ascertain completeness of the on-line documentation and to support authors in locating any gaps. Expe...