An inter-system adapter design is described which links the web service based DR NEP and WebSimP simulation platforms. The adapter enables the PSS Sincal electrical simulator to share results with the DR NEP which coordinates the data exchange among interdependent simulators. In this paper, we describe an adapter which supports decision makers involved in natural crisis management by calculating constraints on electrical loads based on the state of the electrical grid. By eliminating non-feasible electrical distribution options, the adapter reduces the deliberation time and improves the decision outcome. This inter-system adapter can be generalized to other infrastructure systems.