Testing and approval may be appropriate when—

(a) The contractor has not previously furnished the product to the Government;

(b) The contractor previously furnished the product to the Government, but—

(1) There have been subsequent changes in processes or specifications;

(2) Production has been discontinued for an extended period of time; or

(3) The product acquired under a previous contract developed a problem during its life.

(c) The product is described by a performance specification; or

(d) It is essential to have an approved first article to serve as a manufacturing standard.