Need your help in understanding the difference between ACDTIME and I_ACDTIME in agent and split tables in CMS 11

ACDTIME is the talk time for all ACDCALLS that are closed in that interval. And I_ACDTIME is the talk time during that interval on ACDCALLS irrespective of whether the call is closed in that interval or not. However, when we compare total ACDTIME with total I_ACDTIME for an agents entire shift it should be same provided agent is not working day cross over shifts,but I_ACDTIME is much higher than ACDTIME. I can understand the difference between ACWTIME and I_ACWTIME as ACWTIME is only ACW associated with only ACDCALLS and all other UACW will be considered under I_ACWTIME.

Its been a while since I worked on CMS database and custom reports etc however from the top of my head

I_ACD time is an interval calcualtion - usually used for interval based reports - the definition talk time of calls during that interval - regardless of wether they overlap into the next interval. Therfore over an entire day or shift surely there will be a considerable amount of "double counting" of I_ACD time - i.e. if one call spans two intervals then the acdtime is totalled twice.

I dont have a CMS infront of me to check at the moment so I could be just talking rubbish off the top of my head but I think its something like that