KPIs for a Client Planner

A prospective client has asked me to come up with a proposal to sell Client planner services on a fixed price, lump sum basis rather than the traditional hour or day rate. I’m having real trouble coming up with meaningful measures for the SLA (Service Level Agreement), so....

What KPIs can be used to measure the performance of a Client planner?

So far, all I can think of is:

-Turnaround time on schedule review
-Turnaround time on Claim review
-Adherance to agreed reporting calendar

All of which only really measure the timliness of the work, not the quality.

Thanks in advance,

G