::There are too many factors to consider to give a complete answer that isn’t a novel. If you’re moving from object-based Dynamics NAV to Business Central, you have the challenge of converting/re-writing your customizations to AL Extensions. 10-out-of-10 times I would suggest a cloud migration in this scenario. Treat it like a restart on Business Central, and only write Extensions you actually need.
If you are Extension based upgrading, on-premise or cloud doesn’t really change anything. I would still recommend moving to the cloud, but some industries still have some limitations on compliance.
When you view your “upgrade” as a “restart”, you change your perspective on how to approach the project. As a restart, you can make decisions based on the business today, not just bring forward the decisions of the past. Don’t try to recreate the old system, plan out what is optimal for today and the future. This isn’t without challenge, especially if your changing costing methods or utilizing warehousing that you didn’t it the past. It may mean a longer testing phase to get comfortable with the changes.
The project will be what you make it, but make sure you have the bandwidth to thoroughly test scenarios, your Users are excited (throw them a kick-off party?), and remember it is going to have its ups and downs so be ready to work through challenges to get to the finish line.