If you develop websites using WordPress professionally (basically, if you make a living out of it or a significant part of your income comes from there), and you haven’t implemented yet an automatic deployment system, you should strongly consider doing it. Being sincere, it’s not the easiest thing in the world. In fact, both the process and the learning curve will take a lot of working hours out of you, all spent in fruitless tests and dealing with communication between servers. The good thing is that you can take advantage of a lot of resources based on the work of people who lost some sleep hours in exchange of putting a complete deployment system in practice before you have to create a totally new one. There even exist some tools specially designed for WordPress that can be really useful to you.