Glossary
Bringing resources down to the size actually needed, rather than the one chosen when they were created.
Most environments are generously sized, because nobody knew what would be needed at creation time and nobody looked afterwards. Rightsizing compares allocated against used capacity over a longer window.
The basis is measurement across at least two weeks, including peaks and month-end. An average alone is misleading.
How you notice it
Frequently asked
At least two weeks, better a full month, so that month-end and weekly rhythm are included. What matters is not the average but the 95th percentile: downsize by average and you miss the peaks, and you find out on the first campaign day.