From a normalization standpoint it looks good--no huge red flags. So, now to decide if it is right is up to you. Here's a bunch of questions to help you decide :
Does it properly mimic your organization and how it handles stock? Can you put some sample data in it and have it accurately accomplish what you want? Can you get data out of the system in a sensible manner? Did you miss an edge case--sometimes X happens and that means Y should be this, etc?