The phrase "a formal completion" is correct and usable in written English.
It can be used in contexts where you are referring to the official or finalization aspect of a process, task, or document.
Example: "The project requires a formal completion before it can be submitted for review."
Alternatives: "an official conclusion" or "a finalization process."
At a general meeting, 13% of BG shareholders opposed the partnership but not nearly enough to upset a Shell tie-up which is now set for formal completion on 15 February.
The formal completion of the deal will then be on 13 April.
The formal completion of the acquisition closes the book on one of the most intense takeover battles in the UK in recent years.
As it was, Australia could anticipate something rather more than the mere formal completion of hostilities at Durham and The Oval.
Commuters already are experiencing most of the changes wrought by the project, but its formal completion will remind the D.C. region that it is possible for jurisdictions to cooperate on major transportation improvements.
In a country where the military has ruled directly for half of its existence, and often intervened from backstage, Saturday's formal completion of the government's term marked the only occasion one civilian administration stood aside to transfer power to a successor.
Indeed, Savage's achievement amounts to the formal completion of EUT.
This article therefore presents the conceptions formulated by pupils in secondary education in Greece, after the formal completion of the teaching of evolutionary theory.
This study presents research conducted on the conceptions of Greek students regarding issues set out in the theory of evolution after the formal completion of the teaching of the theory.
The ship was commissioned on 8 December 1943 and began sea trials, which revealed many problems that required rectification and delayed her formal completion until 3 May 1944.
