AUC related conceptual problems?

Hi,

I have some question in my mind:

Que: We have asset classes with Investment measure checked but system can't let us make the Asset master if we want to. why?

Que: How do we collect the cost as investment measure, how do we convert it to AUC and how do we capitalize it later?

Plz tell me the complete process with T. Codes etc.

Que: How do we collect the cost in Maintenance and Production order and how do convert that into AUC and then capitalize it?

Que: How do we de-capitalize an asset?

I have tried to read on sites and searched google but I am unable to understand the complete process plz help.

Thanks in advance

Pankaj