Yes, operation is a Scrabble word!

Noun

1. The state of being in effect or being operative
2. A business especially one run on a large scale
3. A planned activity involving many people performing various actions
4. (computer science) data processing in which the result is completely specified by a rule (especially the processing that results from a single instruction)
5. Activity by a military or naval force (as a maneuver or campaign)
6. A medical procedure involving an incision with instruments; performed to repair damage or arrest disease in a living body
7. A process or series of acts especially of a practical or mechanical nature involved in a particular form of work
8. Process or manner of functioning or operating
9. (psychology) the performance of some composite cognitive activity; an operation that affects mental contents
10. (mathematics) calculation by mathematical methods
11. The activity of operating something (a machine or business etc.)