Dr.PeteFamMed said:

The pattern that distinguishes a bad batch from an exit is behaviour rather than product.

Agreed, with a caveat about community reputation: it is a lagging indicator. Reports arrive weeks after orders, so a supplier can look excellent for a month after quality has already changed.

That is the short version; the long version is somebody else's post.

WendyG_ATL said:

True, though the ladder is longer and that is not a neutral detail — six dose steps means six opportunities to stall on the way up, and plenty of…

Bookmarking. The distinction being drawn above is the one nobody else makes. Adding it to my notes with a link back to this thread.

Dr.PeteFamMed said:

The pattern that distinguishes a bad batch from an exit is behaviour rather than product.

I disagree that testing history is decisive. It tells you what a supplier did when they were being watched. Continuity of behaviour under stress — a late shipment, a failed test, a complaint — is more predictive than any run of good results.

One concrete data point for the thread. Keep the original post as written when you update it, and add the correction underneath. An edited-away mistake is invisible to the next person who makes it.

Moderator note: leaving this open. It is being argued well and the disagreement is the useful part.