1. A method of converting a system model with use of a computer in order to facilitate analysis and editing of the system model, the method comprising the steps of: receiving an input of a conversion processing description about a hierarchical multi-dimensional data model structure and extraction queries wherein said hierarchical multi-dimensional data model structure and said extraction queries extract at least one element from a plurality of model elements comprising a graph-type data structure of a graph model of the system model; and generating a hierarchical multi-dimensional data model from the graph model stored in a graph model storage unit on the basis of said inputted conversion processing description, wherein said hierarchical multi-dimensional data model comprises dimensions having a hierarchical relationship.