percentage availability

[eliz_83sg]

percentage availability


I have a problem in crystal report(integrated in visual studio.net)

I want to make a chart which show average of percentage availability based on fault party and date of fault. There are three fault party named Singtel, Sat ops and Customer

availability= (total minutes in a month- total outage)/total minutes * 100

Currently i can show percentage of availability for each party but then when i am trying to get the average, i cannot get the correct result

Below is my formula:
if {dummy.outage}>0 then
if datepart("m",{dummy.date_origin})=01 or datepart("m",{dummy.date_origin})=03 or datepart("m",{dummy.date_origin})=05 or datepart("m",{dummy.date_origin})=07 or datepart("m",{dummy.date_origin})=08 or datepart("m",{dummy.date_origin})=10 or datepart("m",{dummy.date_origin})=12 then
formula = (44640-Sum ({dummy.outage},{dummy.fault_party}))/44640 * 100
else
if datepart("m",{dummy.date_origin})=04 or datepart("m",{dummy.date_origin})=06 or datepart("m",{dummy.date_origin})=09 or datepart("m",{dummy.date_origin})=11 then
formula = (43200-Sum ({dummy.outage},{dummy.fault_party}))/43200 * 100
else
if datepart("m",{dummy.date_origin})=02 then
formula = (40320-Sum ({dummy.outage},{dummy.fault_party}))/40320 * 100
end if
end if
end if
Else
if {dummy.outage}=0 then
formula=100
End if
end if

what i want is let say for january there are 4 faults. 1 fault caused by Singtel, 1 fault caused by customer and 2 faults caused by sat ops.
currently i can show the availability for each party that month(let say for singtel=99.89%, for customer=99.52%, for sat ops= 99.44%), but i can not show the average for that month based on fault party, which is(99.89+99.52+99.44)/3=99.62%

i want the chart shows the average of availability for all months in a year.


How should i approach this problem?


thanks in advance,
elizabeth