Unless the supplier is required to perform a significant part of the contract work with its own forces, it may be difficult to obtain adequate supplier supervision of the work. To address this problem, each Postal Service construction contract must contain Clause B-42: Performance of Work by Supplier, establishing the minimum percentage of the work that the supplier must perform, consistent with customary or necessary specialty subcontracting and the complexity and magnitude of the work. The percentage may be increased for contracts with unusual requirements (i.e., environmental, mechanical).
