Count service instances by multiple criteria

Dear Forum readers,

I have a problem i find a bit tricky to solve with Excel, but i am sure it should be possible.

I have a list of service interventions, every line contains amongst other data the following:
- Products Serialnumber (Unique value pr product, can appear several times if the unit has had several services within the timespan of the report (for instance 1 year)
- Service ID Code (Every service has one unique value)
- Service Closed Date

What i would like to see is if a specific serialnumber has had one or more services within a specific time periode (say 2 months)

I have been bending my mind a bit to try to figure this one out, maybe someone out there can come up with an way to solve it?


Best Regards
Robert

1) As per the Forum Rules, click EDIT on your original post above and correct the title. It should be appropriate to a Google Search on the same issue.

Perhaps: Count instances by multiple criteria

2) The formula will most likely be a SUMPRODUCT() construct.