The complexity of simulation systems has created a challenge for system designers in creating systems that are optimal for both machine and human performance. One of the most useful Human Factors analyses in creating an optimal simulation system is Functional Allocation. While several methodologies exist for Traditional Functional Allocation between humans and computers, many problems exist with current approaches. WARSIM 2000, a computer-based training simulation, has tackled the challenge using computer modeling tools. A new approach, Systematic Functional Allocation, was developed in response to problems identified with Traditional Functional Allocation. This paper outlines Traditional Functional Allocation and its associated problems, provides a general description of Systematic Functional Allocation and describes how the new approach was executed for WARSIM 2000. A sampling of computer models, as well as output reports are provided and discussed. Systematic Functional Allocation has assisted WARSIM Human Factors engineering in making critical design recommendations which have significantly impacted the system design. While this methodology was created specifically for WARSIM, it has potential for use by other simulation systems and domains.