Collocations for operational - adj.

be
become
remain
keep sth
They plan to keep the telescope operational until the end of the decade.

declare sth
The weapon system was declared operational in June 2004.

fully
The equipment is now fully operational.

Operational is used with these nouns:
capability, detail, duty, effectiveness, efficiency, excellence, expense, flexibility, headquarters, independence, manoeuvre, need, plan, readiness, requirement, system