As an introduction, write down your vision for the next 5 years in this chapter. Then set the goals for the first year. (You have a long time ato create the goals for years 2 - 5. They don’t have to be set at the beginning). After that, however, with a release cycle of 3 months, you should also set down the goals for the first release. Again, you then have a whole quarter to decide on the goals for the next release - giving you flexibility if your environment changes or your competitor offers something you want to respond to.

In plain language: It is good to know longer-term goals as well. However, you only need to specify them to the extent that they are needed for the next time periods. Nevertheless, it helps everyone involved to know where the train is going - even if that may still change.