Is it possible to engage business on reviewing regression test pack/high level test scenarios? What is an effective way to do this?

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Yes, stale tests are a problem many have faced before. See also some of the discussion tangents in

When people ask this question I get the impression they are testing a non-web product, and they are testing the entire product and not focusing on features. Both of these kinds of work are expensive and exhausting, if… if there isa priority or order in which tests get executed, I would look at using that. Any tests at the end of the run and lower down, are probably not worth running every time, and that’s what I would be culling if possible. Giving tests priorities or ordering helps a tonne.