You can have multiple years open at the same time. There is no roll-forward process.
If you're working with multiple asset years and make a change to an earlier year, the changes automatically flow through to subsequent years.
For example, you've finalised your client's asset register and are drafting management accounts for the year 2016. Your client calls and tells you that they've forgotten to tell you about the new laptop they purchased in the 2015 financial year. Because of the multi-year functionality, you can easily open the 2015 financial year and add the laptop purchase. If you then open the 2016 register, you see that the laptop is there with the correct opening written-down value.