Recently, we have introduced and modified graph-decomposition theorems based on a graph product motivated by applications in the context of synchronising periodic real-time processes. This vertex-removing synchronised product (VRSP) is based on modifications of the well-known Cartesian product and is closely related to the synchronised product due to Wöhrle and Thomas. Here, we introduce a new graph-decomposition theorem based on the VRSP that decomposes an edge-labelled acyclic n-partite multigraph where all labels are the same.