The validity of hardware sizing
Pegasystems provides hardware sizing service and it gives a thick PDF file that describes the hardware resources such as RAM, storage size, and CPU. I usually use this at early phase of a project to get a rough idea of what kind of hardware client has to purchase. However, I never thought it as the solid resources that client could rely on but it has to be always validated by actual load test because no one call tell how much of memory would be consumed depending on how developer codes.
However some client believes in this sizing output as it is very solid, reliable metrics that would not really change after development. I just wanted to get some insight upon how actually people see this hardware sizing output?