The Players and the Vocabulary

The nouns that change a meeting

A forecast estimates future demand under stated assumptions. Give it an as-of date, because the information available at the time is part of what makes the estimate interpretable. Revising it after a customer changes plans may be exactly the right thing to do; the revision is a new forecast, not evidence that the old one was accurate. Check the unit, too: in a Finance meeting “the forecast” usually means expected spending for the year, and in a capacity meeting, demand in requests, cores, or tokens.

A target is something the organization intends to achieve. A sales target may be deliberately ambitious to encourage people to pursue an opportunity, while the most likely estimate of realized demand is lower. Capacity needs to examine the target as a scenario without silently converting ambition into a prediction.

A budget is an approved plan for spending: an amount, for a period, held by someone accountable for it, usually set months before the demand it funds. It doesn’t approve a particular purchase. Who can approve that kind of spending, and whether the amount crosses a threshold that sends it through a different process, are separate questions, and often what Finance means by “it depends.” Whether the money will support the service’s obligations is an engineering and business question, and a discrepancy between the two needs a conversation rather than a revised label.

A request says what someone wants and starts an investigation or a negotiation. It doesn’t establish that the resources exist, that funding has been approved, or that another customer will give up an allocation, which sounds obvious until a requested amount starts appearing in other people’s plans as confirmed supply. Requests also lose their reasons on the way: the SRE book’s account of Auxon, a Google planning tool, describes requests arriving as “X cores in cluster Y,” their degrees of freedom “long lost.”² In our launch, the degrees of freedom were most of the answer. A quota increase says no more about supply: it raises the limit on what we may request without putting any machines behind it.

A reservation needs to be understood in its particular context. It might be a provider product, an internal hold, or a position in a planning queue, and a provider’s reservation may buy a discount, a hold on capacity, or both. I want to know what has been reserved, for whom, where, for which dates, and with what release rule before I use it to support a customer promise.

A commitment is a promise with defined parties and conditions. In Volume II, Chapter 20 we will separate a promise to spend from a promise to supply usable capacity, because each can exist without the other. An optimistic forecast in a presentation establishes neither.

One more noun is not a planning word but a product word, and meetings trip over it as often as the others: the SKU. The term is stock-keeping unit, borrowed from retail, where it names one distinct item a store sells — one product, in one configuration, that someone can order by a code. The cloud providers borrowed it for their catalogs, and in this book a SKU is one sellable configuration of a service: one size, one feature set, one price. Every line on the bill in Chapter 1 names a SKU.

The name is worth reading slowly, because providers encode the machine into it. In Microsoft’s convention, Standard_D4s_v5 decodes as a general-purpose family (D), four vCPUs, premium-storage capable (the s), fifth version (v5), and the encoded extras run to local disks, network bandwidth, memory ratios, processors, and, for the accelerated families, the accelerator model itself: the GPU size Chapter 10 works with, Standard_ND96isr_H200_v5, announces the H200 in its own name.³ Other providers publish naming conventions of their own, and the skill of reading them transfers even where the grammar differs.

Explore this in the full chapter →