The substantial arrangements determination only applies to Self-Employed persons seeking to claim Moving Expenses. For a typical employee of a company, the change in companies or location serves as proof that the move was work-related. This is a bit harder for filers who are considered self-employed.
If you are self-employed, have moved for business/work purposes, and wish to deduct moving expenses then "substantial arrangements" vary on a case-by-case basis, but here are some examples:
(i) Leased or purchased a plant, office, shop, store, equipment, or other property to be used in the trade or business
(ii) made arrangements to purchase inventory or supplies to be used in connection with the operation of the trade or business
(iii) entered into commitments with individuals to be employed in the trade or business
(iv) made arrangements to contact customers or clients in order to advertise the business in the general location of the new principal place of work.