still on dynamics NAV 2013 (R2)?
so you are still on dynamics NAV 2013 or NAV 2013 R2 or even earlier? and happily so? nothing wrong with that, but you should be aware of an important date: the end of mainstream support for your product. if you are anything similar to most of the companies using NAV, you paid a considerable amount of money and time to get things up and running. if so, you probably don't want to put your investment at risk.
you might say: ah! 2018! plenty of time left. over one and a half years. but don't be mistaken. upgrading and implementing the newly available features will take some time. and you want to get this done smoothly and without much overtime for the users? then you better don't wait too long and start planning soon.