The summary.
DECIDE PER WORKLOAD
Not for the business as a whole. Most businesses end with a deliberate mixture.
WHERE TO START
Email and file storage. Clear benefit, well understood, straightforward.
Defer anything critical and complex until you have experience.
TEST WITH YOUR OWN DATA, ON YOUR OWN CONNECTION
Demonstrations show the service performing ideally. Trial the actual work you would do.
Involve the people who will use it, or nobody will.
BUILD THE COMPARISON HONESTLY
Include administration time and downtime in the current arrangement — both are usually omitted and usually substantial.
Project three years. Cloud costs recur; a purchase does not.
WHAT AN SLA ACTUALLY GIVES YOU
Service credits, not compensation for lost trading.
Assume outages will happen and plan for them.
ESTABLISH THE EXIT BEFORE THE ENTRANCE
How you export your data, in what format, and what it costs to move it out.
An export you cannot use is not an export.
THERE IS NO OBLIGATION TO MOVE
If the current arrangement works and is affordable, that is a legitimate answer.
