Tennessee Code Title 5. Counties § 5-14-112

(1) Classify the requirements of the county government for supplies, materials and equipment;

(2) Adopt as standards the smallest number of quantities, sizes and varieties of such supplies, materials and equipment consistent with the successful operation of the county government; and

(3) Prepare, adopt and promulgate written specifications describing such standards.

(b)(1) In the preparation and revision of such standards, the county purchasing agent shall seek the advice, assistance and cooperation of the county departments and agencies concerned, to ascertain their precise requirements.

(2) Each specification adopted for any commodity shall, insofar as possible, satisfy the requirements of the majority of the county departments and agencies that use the same.