Workload Assumptions: The same pricing and budgeting assumption caution applies to workloads. Look carefully at your current utilization and consider how much resources those same workloads would consume in the new environment. There’s a lot to consider. For example, reading a record from a properly designed relational database takes a single lookup. Reading a record from a flat file in a data lake could require sequentially reading many large files. I recall a study completed iran rcs data about a decade ago that found that the total cost to answer certain questions in (low-cost) Hadoop was comparable to the cost to answer that same question in a (high-cost) relational database. the workloads in your current environment will require significantly greater resources in your new environment, whether it’s because you have to construct the solution differently, or run multiple queries or applications, or access more data. Other questions you should ask include: Can the workloads be optimized? Can the environment be designed to reduce resource requirements? And can users be educated to be more efficient (and is that a realistic expectation)?
Pay very close attention to the utilization and workload assumptions. One miscalculation can negate all of your invoice cost savings.
This is especially true with a cloud migration where stories of extreme unexpected cost overruns are so common as to have become cliché.