The phrase "upon a completion" is correct and usable in written English, and is typically used to refer to the completion of an action or task.
Example sentence: Upon a completion of the assignment, the student was rewarded with an A.
If he is to validate last season, he will need to match or improve upon a 65.3 completion percentage (second in the N.F.L).
The British Boxing Board of Control has said Hatton will be granted a licence upon completion of a medical.
On larger jobs, such as a room addition, the payment will be broken into thirds at certain "benchmarks", such as one third upon beginning, a third upon completion of framing, rough plumbing and rough electrical, and the final third upon completion.
Therefore, to identify the best in-use channel to release, the criteria for reassigning a channel upon the completion of an ongoing call are as stated below.
During its construction, workers experienced accidents and odd events, and, upon its completion, a mysterious entity destroyed his beloved collection in the dead of night.
In this pilot study, a PGA was performed by a single clinician upon completion of an outpatient clinical encounter and again after receipt of pertinent laboratory values.
A live seminar presented by two physicians and a clinical nurse specialist was strategically used to enhance learning, and participants completed an evaluation upon completion of the seminar.
These pieces are reassembled by a special torrent program upon the completion of a download.
However, users would only be able to earn badges, a college credit, or a certificate at best, upon completion of a course.
Simultaneously, the brigade converted to a modular structure to become a Brigade Combat Team upon completion.
