What are the most important Information Technology Milestones for Business Organisations?

Hey there,

I am in the mids of a research about the change management frameworks and models used for Information and Communications Technology (ICT) introductions in organisations and currently aim to read about as many past such efforts as possible.

Therefore, I'm looking to hear from experts what are the most important ICT innovations in the context of business organisations?

Furthermore, if you have any suggestions on papers about the change management techniques around the way these tech advancements were implemented, please share them.

Thank you very much in advance!