Hello,
I find my self lost in the equipment numbers with these questions: why does the equipment have serial number plus his number .. why do they have many serial numbers? .. isn't serial number refer to something unique..used one time and not changeable !!
Also when trying to view an equipment (tcode ie03) I got the screenshot below 
and when I click history I got this :
Now.. for me, and by logic I'm supposed to find the current and the last serial number of this equipment also in the history, but they are not there ! can you explain me why ..?
Regards
Khadija