Ideas for building chart

[vxxv]

Hi,

I've a problem on how to build a chart. I work with CR 8.5 and I need to count the number of occurrences that wr_id has. But that number depends on verifying some aspects.
My table has some fields like (the ones that I need to check):
wr_id;pmp_id;pms_id;prob_type;date_issued;status;
date_completed

To count the wr_id's I need to separate them by:
1) Those who have pmp_id null and pms_id null and prob_type <> 'PREVENTIVE MAINT' are the "Corrective".
2) Those who have pmp_id not null and pms_id not null and prob_type = 'PREVENTIVE MAINT' -> are the "Preventive".

Then I need to count, for the Preventive ones and for the Corrective ones the respective wr_id's that has these restrictions:
a) not issued: date_issued is null and status = 'AA' and date_completed is null;
b) active: date_issued is not null and status in ['I','HP','HL','HA'] and date_completed is null;
c) complete: date_completed not null and status in ['COM','CNC','CLO'] and date_issued is not null.

If anyone has some ideia to help me I'll be very grateful.

Thanks,
Jaime