Application modeling is a major part of IS development. Often the application models are used directly in the implementation. However, most traditional modeling methods are incomplete, and ad-hoc methods are used to `fill in the gaps'. As industry dependence on software increases, software quality becomes paramount, and such informal practices are no longer adequate. Model integration is a favorable approach to resolving these problems. This paper examines using a metamodel to provide automatic integration support for traditional modeling methods. The idea is explored in a case study that uses NIAM and Petri-Nets to model a simple Student-Subject enrollment system, and Object-Z to integrate them.