This is an interesting challenge!

You'll need to use a stacked bar chart and you'll place it in an Group or Report Footer (or possibly Header - NOT in Details!) You'll also need an employee group so that you can count the number of requests per employee.

Then you'll need something like these formulas:

{@NumComplete}
if {MyTable.TAT} < 30 then 1 else 0

{@NumNotComplete}
if {MyTable.TAT} >= 30 then 1 else 0

{@PercentComplete}
if DistinctCount({MyTable.RequestId}, {MyTable.EmployeeGroupField}) > 0 then
Sum({@NumComplete}, {MyTable.EmployeeGroupField}) % DistinctCount({MyTable.RequestId}, {MyTable.EmployeeGroupField})

{@PercentNotComplete}
if DistinctCount({MyTable.RequestId}, {MyTable.EmployeeGroupField}) > 0 then
Sum({@NumNotComplete}, {MyTable.EmployeeGroupField}) % DistinctCount({MyTable.RequestId}, {MyTable.EmployeeGroupField})

You'll then graph the two "Pct" formulas per employee and change the color of the bar to green and red.

-Dell