ISO 22000 for an international franchised company

I am aiming to create a master manual against ISO22000 for corporate but am having difficultly getting my head around how to manage the multiple franchise owners in terms of compliance against our standard expectations. There are all different sizes of franchisee involved too, large corporate companies, medium sized and small (as small as one franchise).

If they are all doing the same thing (product/process) no matter the size there can be a core set of policies and procedures that apply to all. Can you be more specific with your query?

Regards,
Simon