email alert when pending jobs exceed certain limit in BI4.1

Hi,

How can we setup an alert which will send an email if the number of pending scheduled crystal report jobs exceed a certain limit.

we have 4 AJS (each can take max 5 jobs), so maximum 20 jobs can run simultaneously and other jobs will be in pending status. I want an email alert which should trigger if the pending jobs exceed 200.

Version : BI4.1

Thanks