DSMs were later extended to Domain Mapping Matrices (DMM). The goal was to enable matrix methodology to include not just one domain at a time but to allow for the mapping between two domains. DMMs are thus rectangular matrices, and they can be binary or numerical again.
In the figure below, the process example is extended to show who is responsible for which task. The DMM on the left hand side shows how these persons can be mapped to the tasks.
The Design Structure Matrix (DSM) 