When thinking about viability, it means that things are capable of being completed in a practical/useful manor, so when creating a music video you will have to consider whether or not you will have/do currently have the right resources and materials that you will need to create what you are, you will also have to consider if it is too difficult and whether or not you will actually be able to complete it, if not you may have to re think segments of the idea or the whole entire idea completely. All of your ideas have to be practical/realistic, these ideas must be throughly thought through and checked before any real plans can go ahead, or you could end up wasting a lot of time and or money on ideas that do not end up working out the way you wanted or do not fit in with the music video in the end. Also coming up with a contingency plan/s is a good move, the music video not working out could happen and having a backup or even a few could come in great use.
