At United Parcel Service, Inc., rules are religion. Without them, UPS could never move 13.5 million packages to their destinations on time each day. But two years Mark J. Colvard, UPS man- ago, a ager in San Ramon, California, had to decide whether to buck the system. A driver needed time off to help ailing family member an but under company rules he wasn't eligible. If Colvard went the by book, the driver would probably take the days anyway and be fired. If Colvard gave him the time off, he would catch flak from his other drivers. Colvard wound up giving the driver two weeks, took some and kept a valuable employee.