The paper proposes a layered architectural framework to support agent based system development in a collaborative, multidisciplinary engineering setting. This architecture is viewed from two distinct perspectives. First, the environment must enable agent based modeling and simulation. Second, it should support concurrent (team oriented) engineering. The main focus is on the proposed layered architecture delineating various needs of an agent based system, thus supporting incremental specification design, implementation, and testing. In our discussions, we distinguish between performing agents and simulated agents. The former refers to agents as they are performing their tasks in real-world settings. The latter refers to agents that have their behavior simulated in a virtual environment. In these terms, the proposed framework is intended to form the basis for environments that support development of agents, in both performance and simulation modes, as well as in hybrid combination (both performing and simulated agents interacting at the same time). The proposed framework is a step toward realization of agent based systems under the umbrella of the simulation based acquisition (SBA) initiative of the US Department of Defense.