Technology Radar
A published, periodically-reviewed view of which technologies are endorsed, tolerated, being trialled, or to be avoided.
The problem it solves is the two failure modes of technology governance: an approved list so rigid that teams route around it, and no guidance at all, producing an estate with four message brokers and nobody able to support any of them.
The four rings — adopt, trial, assess, hold — give a middle path. Adopt is the default choice with support and expertise behind it. Trial is being used in production somewhere with a sponsor. Assess is worth an experiment. Hold is do not start anything new with this, which is not the same as ripping it out.
What makes it work rather than becoming shelfware: dates and movement (things must progress between rings or be removed), a named owner per entry, a stated reason for each placement, and a real route to propose a change. A radar published once and never revised is worse than none, because teams stop trusting it and revert to deciding alone.