Content Manager service response time high watermark over 12 minutes

[Invisi]

I am monitoring Cognos 10 at my new client. One thing I see here (and also previously with other clients) is that the response time high watermark of the Content Manager service is very high, in this case over 12 minutes. What causes this? My first guess is that Content Manager has multiple requests per report, so when the number of requests is full somehow, it gets locked. Who can tell me how it works and how I can improve it?