Hi AX2009 User,
What I could think of to get this resolved is using different value models to track the different lifetimes and values of your assets. If you are not linking those value models you can even track different acquisition costs and depreciation, etc. for one single asset. As an example, a value model 'wear and tear' could be setup with an acquisition value of 1000 and be depreciated over 5 years while a 'tax' value model could hold an acquisition value of 800 and be depreciated over 8 years.
If you find this confusing, setting up two separate single fixed assets might be the better choice.
This setup can be realized by setting them up manually or - as you write - by splitting one fixed asset into several ones.
Please note that split in this context means that the total value is reduced by the one that is split.
If you could provide a concrete example, we could probably be more concrete than just mentioning possible options/Features in AX that might help.
Best regards,
Ludwig