Rewrite this sentence making it sound more formal:
"He didn't do the assignment as expected."
Contrary to expectation, he did not complete the assignment with the required standards.
Complete the following task based on the instruction and optional input provided.### Instruction:
Rewrite this sentence making it sound more formal:
"He didn't do the assignment as expected."

### Output:
Contrary to expectation, he did not complete the assignment with the required standards.