Synonyms for Operational (same or very similar meaning)
WordNet sense 1 (fit or ready for use or service):
functional, operable, usable, useableWordNet sense 2 (ready for service or able to give long service):
serviceableWordNet sense 3 (being in effect or operation):
operatingWordNet sense 4 (being in force or having or exerting force):
operativeFrom the ODE community, based on WordNetadd/edit