transistors - How is an NPN relay switch circuit analysed?

So I came across this good article: https://www.electronics-tutorials.ws/blog/relay-switch-circuit.html
It gave me a good insight into the different transistor-relay switching circuits. But unfortunately, it hasn't provided any detail regarding the analysis of such circuits, more specifically the NPN relay switching circuit.


Above is an image from the article, of an NPN relay switch circuit.

The only way I can think of working through the circuit is by modeling it as shown below and then analysing it:

I haven't analysed such a circuit before and would love to know what the general approach is.