Abstract
As a formal goal selection method, Goal-Oriented Requirements Engineering (GORE) approach has received much attention. The artifact of GORE is a directed acyclic graph which is called goal graph. Because any analysis in GORE is basically based on goal graph, goal graph needs to be defined strictly. However, as far as author can tell, no attempts to define goal graph as a hypergraph has been done. Goal graph is a AND/OR graph and AND/OR graph is defined by a hypergraph. Therefore, it is valuable to define goal graph as a hypergraph as a foundation to apply existing study results of AND/OR graph to GORE. For this reason, the result of an attempt to define goal graph mathematically as strictly as possible is stated in this paper.
