Finance, stock, staff and purchasing all live in different places.

An ERP is one system that runs the core of a business: money, stock, purchasing and people. Instead of re-typing numbers between tools, every department works from the same records.

It is a strong, low-cost choice for many growing businesses. It works best when it is configured around your process rather than heavily modified. A short discovery shows whether it fits or whether something custom is better.

Rarely because of the software. They fail when a system is forced on people, when old data is moved across without cleaning, or when everything goes live at once. Going in stages with training on real data avoids most of this.

Yes. ERPNext and similar systems handle several branches, warehouses and even separate companies in one place, with each person seeing only what they should.

A few changes may be worth making, and you will hear which ones and why. But the system should fit your business, so most of your process stays as it is.

It depends on how many departments and how clean your data is. Going live in stages means the first department can be using it early, instead of waiting for one large launch at the end.