Business{IT alignment is an ongoing activity of high importance for the success of a business. This is a hard task, especially in the context of value webs in which multiple businesses collaborate with each other to reach a common goal. Value models, as the outcome of the value web exploration phase, represent solutions for business people, but not for software engineers. The latter ones have to come up with a blueprint for the implementation at application level. This can have two faces: Either there are no systems at all and everything needs to be designed from scratch, or it is desired to use as many existing systems as possible. In the latter case, on which we focus in this paper, it must be checked which functionality existing systems should provide and whether they are usable for the given value web context. This affords several design activities, as well as checking consistency between di®erent models. Our approach can be viewed as an alignment checking method and also as a gap analysis, in case existing systems miss a given functionality.