Proof of concept quality metrics

Hi all,

Looking to field some views on quality metrics.

Dev team are building a subset of functionality of a system within a timeboxed period. We will look at the rate of and quality of development to assess whether we can build the remainder to time and cost or if we should take an alternative approach.

What quality metrics would people suggest? (I have some in mind but there is some debate, keen to field ideas without influencing) for each metric what allowances should be available?

We are expecting unit and system tests to take place.

Cheers