With the launch of the first element of the International Space Station (ISS) in late 1997, scientists and engineers from around the world will have greater access to the space environment for research and commercial exploration. The complexity and flexibility of the International Space Station offers opportunities as well as challenges in planning on-orbit operations. In order to make effective use of limited resources (e.g. crew time, power, and data), while maximizing the results to the scientific, commercial, military and educational communities, the ISS operations planning community must balance many constraints and criteria. The four disciplines must be aware of these constraints as well as the planning process to plan and conduct their activities on-board ISS