What is paging space in AIX?

I get that Paging Space in AIX is actually like SWAP in Linux. In one of my AIX servers at work, i'm actually seeing 99.7% Physical memory being utilized when my application is running(handling quite some data). Most of the time Server is utilizing 95% of Physical memory(RAM). From the pic attached, we can see Paging Space is being utilized. And i believe my Application can run little faster if i upgrade RAM. But i am not able to convince the management. They say that still Paging Space is there and until it's utilized fully, no need to upgrade RAM. Isn't paging Space actually in Hard Disk ? OS actually transfer data between Paging Space(Hard Disk) & RAM back & forth in case of High Memory Utilization ? Can someone please shed light that if i am using up 99.7% of Physical Memory - RAM in Server,it's a Good reason to upgrade RAM ? Note: I'm posting here as a last resort and in need of proof to convince my management to upgrade the RAM in my server before Christmas, as i will be seeing quite a lot of data during Christmas. So Please, before down-voting, at least help me what's wrong with my question and help me get an answer.