Hi,
As started by the ganesh first use the standard data sources.
0HR_PA_0
0HR_PA_1
if not available in standard data source ask the functional team HR they would maintain the some custom tables.
create the generic data source using tables then transport to BW system.
while designing the data model use the one KF with constant 1 at target level.
at transformation use the constant 1 using the rule details.
it will give the total count of employees.
then design the query use the exception aggregation - counter for all detail values that are null or zero.
reference char -> employee.
hope it will help.
Thanks,
Phani.