Will you support systems you did not build?

The monthly arrangements are only offered after my own set-up, and the reason is responsibility rather than salesmanship: a retainer is a standing promise that the record can be relied on, and I cannot make that promise about a system I have never read. A system built elsewhere, whether by your own team or by someone else, is not turned away; it starts with a review like anything else, which reads what is actually there, what it captures, where it drifts and what it would take to bring it onto a supportable footing. Sometimes the honest finding is that it is sound and needs only small changes, and the write-up says so. What I will not do is inherit a black box and invoice monthly for watching it, because the month something went wrong, the promise would turn out to have been decoration.