In an organization that practices the "you build it, you run it" principle, a definition of production readiness (DPR) is a useful technique to support teams in assessing and preparing the operational readiness of new services. Implemented as a checklist or a template, a DPR gives teams guidance on what to think about and consider before they bring a new service into production. While DPRs do not define specific service-level objectives (SLOs) to fulfill (those would be hard to define one-size-fits-all), they remind teams what categories of SLOs to think of, what organizational standards to comply with and what documentation is required. DPRs provide a source of input that teams turn into respective product-specific requirements around, for example, observability and reliability, to feed into their product backlogs.
DPRs are closely related to Google's concept of a production readiness review (PRR). In organizations that are too small to have a dedicated site reliability engineering team, or who are concerned that a review board process could negatively impact a team's flow to go live, having a DPR can at least provide some guidance and document the agreed-upon criteria for the organization. For highly critical new services, extra scrutiny on fulfilling the DPR can be added via a PRR when needed.