Verifying the On-line Help System of SIEMENS Magnetic Resonance Tomographs

Large-scale medical systems—like magnetic resonance tomographs—are manufactured with a steadily growing number of product options. Different model lines can be equipped with large numbers of supplementary equipment options like (gradient) coils, amplifiers, magnets or imaging devices. The diversity in service and maintenance procedures, which may be different for each of the many product instances, grows accordingly. Therefore, instead of having one common on-line service handbook for all medical devices, SIEMENS parcels out the on-line documentation into small (help) packages, out of which a suitable subset is selected for each individual product instance. Selection of packages is controlled by XML terms. To check whether the existing set of help packages is sufficient for all possible devices and service cases, we developed the HelpChecker tool. HelpChecker translates the XML input into Boolean logic formulae and employs both SAT- and BDD-based methods to check the consistency and completeness of the on-line documentation. To explain its reasoning and to facilitate error correction, it generates small (counter-)examples for cases where verification conditions are violated. We expect that a wide range of cross-checks between XML documents can be handled in a similar manner using our techniques.