There are many factors to consider when engineering access and short-haul millimeter wave radio paths in relation to rain fading and traffic outages. Long-established reference models, sophisticated software and high-speed computational devices can help narrow the decision-making window for the microwave transmission engineer. However, much also depends on the end-use applications and overall objective for any particular microwave network. Microwave transmission engineers have to use their experience and professional judgment in determining how to best use these rain fading and outage tools for their specific networking projects. This white paper examines some of the classic models and pertinent mission questions for microwave radio network rain fading and outages.