An order denying class certification or striking class allegations is not a final or appealable order. The aggrieved party may seek discretionary review of such an order under Federal Rule of Civil Procedure 23(f) or 28 U.S.C. § 1292(b). However, here plaintiff followed neither of these approaches but instead had the district court certify the order striking the class allegations under F.R.Civ.P. 54(b). This certification did not work because the certified order did not finally resolve one or more of the claims. Rule 54(b) does not give the trial court discretion to make an interlocutory order appealable. Hence, the Court of Appeals lacked jurisdiction of the challenge to the order striking the class allegations.