What software can I use for this?

[Mr Jack]

Microsoft Visio

Visio is a great tool for this, if you have access.

If you don't Word has SmartArt templates for org charts? Or my old boss did something similar with Powerpoint, although it was always really messy.

 

[Trifid]

Lucid chart > Visio imo. I tend to get a bit too excited about the need to create a chart or other visual document with Lucid chart then I probably should admit to...