13. The method as claimed in claim 12 , wherein the configuration of the plurality of modules is recognized as being valid if each type module and each variant module within the configuration meet prescribed validity criteria.
13. The method as claimed in claim 12 , wherein the configuration of the plurality of modules is recognized as being valid if each type module and each variant module within the configuration meet prescribed validity criteria. 15. The method as claimed in claim 13 , wherein the validity criteria tested for a variant module in a configuration are: whether each type module selected as being subordinate to this variant module meets prescribed validity criteria, whether each condition associated with the variant module is met, and whether the type modules in the configuration which are selected as being subordinate to the variant module are only those which are admissibly made subordinate to the variant module in accordance with the configuration structure.