Partial retirement of assets, qty is not adjusted with the removed assets

Hi Gurus,

when we create an Asset with 4 units with an amount of 9000 and costs would be (1-1000,2-5000,3-2000 , 4-1000) and if i want to retire 2 number unti with amount of 5000 and phyiscally  there would be only 3 units are available but system shows the remaining units under the asset as 2 ,but business wants the system shows the remaining assets as 3 .

so, what will be the solution for resolving this issue that system shows remaining 3 units only.

Thanks in Advance.

Best Regards,

Dhanunjay