Had a student do a research thesis on this last year and IIRC whether
it's a massive cost saver or an expensive disaster boils down to good
old fashioned "system analysis".
Know your system, every part. Big cost savings are often made at this
stage just discovering a shit-ton of obsolete stuff.
Don't just map the network, map the _function_ of the network. Then
look at its logical versus physical topology for anomalies (also a
great security exercise).
What you bring back on-prem must be systematically viable.
Factor in on-prem energy costs, they are not trivial.
The biggest overall factor is people and wages. Any significant
repatriation project ends up needing to hire back the system
administrator you fired a couple of years ago.
Know your system, every part. Big cost savings are often made at this stage just discovering a shit-ton of obsolete stuff.
Don't just map the network, map the _function_ of the network. Then look at its logical versus physical topology for anomalies (also a great security exercise).
What you bring back on-prem must be systematically viable.
Factor in on-prem energy costs, they are not trivial.
The biggest overall factor is people and wages. Any significant repatriation project ends up needing to hire back the system administrator you fired a couple of years ago.