operational

adj. 1. of or pertaining to operations; as, operational procedure. [ WordNet 1.5 ]

2. Fit or ready for service; available and in working condition; as, an operational aircraft. Opposite of out-of-service.
Syn. -- functional, usable, useable, in order(predicate), in working order(predicate), operable. [ WordNet 1.5 ]

3. (Mil.) of or intended for or involved in military operations. Opposite of nonoperational. [ WordNet 1.5 ]

4. In force; not expired or annulled; -- of rules or laws. [ WordNet 1.5 ]

de facto apartheid still operational even in the `new' African nations Leslie Marmon Silko [ WordNet 1.5 ]

n. (Philos.) the doctrine that the meaning of a proposition consists of the operations involved in defining, proving, or applying it. [ WordNet 1.5 ]