Nearly all law departments are staffed so leanly that little time exists for their busy lawyers to train backups. Lawyers fill specific roles, their plates are full, and there is not time to cross train someone just in case (See my post of June 24, 2007: intractable management problem of career paths; Sept. 1, 2008: learning methods with 12 references.); and May 21, 2008: how generalists can learn from specialists.).
It sounds good in theory to cross-train, but the demands of real life intrude too frequently and squash the good intentions. For that reason, general counsel can fall back on several partial substitutes for training someone to backfill a position.
One method is to rotate lawyers among positions (See my post of Aug. 26, 2007: rotations as experiential learning.). Another method takes a process view. The more a law department systematizes its processes, the easier it is for someone to step in and take over for a departed lawyer (See my post of June 6, 2008: standard, routine and systematized services.). Third, to the degree a law department sets up knowledge management resources, the better it can transition workload to someone new in a role. The more communication there is within a law department, furthermore, the closer it comes to cross training for the reason that some of the know-how is available and familiar. Typical methods for substantive communication within a legal department include group e-mail lists, intranet sites, bulletin boards, staff meetings, and periodic conferences or call-ins.