No. "Materials and supplies" under MCL 208.1113(6)(c) means tangible personal property acquired during the tax year to be used or consumed in - and directly connected to - the production or management of inventory under MCL 208.1113(6)(a) or the operation or maintenance of assets under MCL 208.1113(6)(b).

"Assets" as defined under MCL 208.1113(6)(b) mean those "acquired during the tax year of a type that are, or under the internal revenue code will become, eligible for depreciation, amortization, or accelerated capital cost recovery for federal income tax purposes."

There is no requirement that assets need to be related to inventory to qualify as a purchase from another firm. Moreover, there is no requirement that materials and supplies used or consumed in the operation or maintenance of assets are only deductible to the extent that such materials and supplies are used or consumed in the operation or maintenance of assets used to produce or manage inventory.