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The Quality Death Spiral


Term Definition
FCS First Customer Ship
gate Source code repository
Put [it] back Committing code to the gate


Jeff Bonwick was the gatekeeper for Solaris 2.5. He gave a talk on Solaris to the Sun Systems Group in September, 1994. It included a section on the Quality Death Spiral -- a timeless phenomenon that remains our omnipresent fear:

The following is paraphrasing Jeff's talk.

If it's broken, rip it out!

  • FCS quality all the time
  • Put it back today, 20 of your (current) friends will be running it tomorrow
  • Gate breakage grinds other development to a halt
  • The product, not any one project, is what matters
  • Mistakes will happen; negligence cannot

FCS quality all the time

Why is this so important?

Only way to avoid the quality death spiral:

  • People hear the gate is broken
  • Decide not to risk a bringover
  • Fewer people run the latest stuff
  • Less real-life testing
  • New bugs not found
  • Quality drops further

  • Morale tracks quality

  • Downward spiral hard to break
  • Recovery time can be very long

Originally sourced from