Minor quibble unrelated to the main content of the post: the measures are not fixed costs of assets, but a blend of depreciation and the operating cost of power usage for those assets. Sort of a regular snapshot of an average daily accounting cost, so to speak (which is reasonable). And this was cost to Google, not taking into account what Google could make by charging Cloud customers for the use of those assets (opportunity cost).
My understanding is that the main use of this tool was actually for engineers to give reasonable-ish impact statements for their performance work. I hadn't heard of anyone using it to make serious trade-offs in project planning, since at the level where that matters, the capacity planning teams had more precise costs related to their actual budgets, as well as short term goals like "RAM has a supply chain shock so we can't get any more than X for the next quarter."
Also a pet peeve of mine, people constantly screwed up the units. "10 SWEs" is rate (cost per time), same as "10 TB of RAM", but "SWE-years" is cost (ie dollars). Many design documents use these inconsistently.
Minor quibble unrelated to the main content of the post: the measures are not fixed costs of assets, but a blend of depreciation and the operating cost of power usage for those assets. Sort of a regular snapshot of an average daily accounting cost, so to speak (which is reasonable). And this was cost to Google, not taking into account what Google could make by charging Cloud customers for the use of those assets (opportunity cost).
My understanding is that the main use of this tool was actually for engineers to give reasonable-ish impact statements for their performance work. I hadn't heard of anyone using it to make serious trade-offs in project planning, since at the level where that matters, the capacity planning teams had more precise costs related to their actual budgets, as well as short term goals like "RAM has a supply chain shock so we can't get any more than X for the next quarter."