Originally Posted by Happy

If you refer to the availability for EACH segment, then the usual BA, QF, JL, CX award booking engines all will work to find partner seats - not 100% match with AA's inventory, but close. Personally I like BA's the most, especially now they give info on how many award seats remain.

If you refer to the routing, then the Oneworld Interactive Route Map is a great tool to let you see what OW member operated flights on the itinerary you want to do. Keep in mind you cannot use code-share, so only the Blue routes can be used. The map gives you very detailed information and it is a great tool to map out the possible routes.

If you refer to the total mileage calculation, the mileage calculating sites such as Great Circle Mapper is what you need. Keep in mind you need to input EVERY Actual Segment you will fly to calculate the total mileage - no more beeline calculation.

Putting a workable route together is by far the hardest part - when I mean workable, I mean it is not just a legal routing, but a routing you most likely to find seats. There is no point to have a legal routing in theory but it is near impossible to find seats. Therefore, checking segment availability from the outset when you start designing the route is important so you would not waste your time.