WordNet sense 1 (of or intended for or involved in military operations):

operational

WordNet sense 2 (marked by qualities giving the power to produce an intended effect):

efficacious

WordNet sense 3 (producing a strong effect):

impressive, telling

WordNet sense 4 (characterized by or full of force and vigor):

trenchant

WordNet sense 5 (producing or capable of producing an intended result or having a striking effect):

effectual

WordNet sense 6 (exerting force or influence):

good, in effect

WordNet sense 7 (being in force or having or exerting force):

operative

WordNet sense 8 (able to accomplish a purpose; functioning effectively):

efficient

WordNet sense 9 (properly or sufficiently qualified or capable or efficient):

competent

WordNet sense 10 (presently existing in fact and not merely potential or possible):

actual, existent