We have built many projects, and we believe the most valuable summary indicators are:
• Dτ = Delivery lead time. Product teams may say "from concept to customer" or "from idea to implementation".
• Dμ = Delivery service rate. Devops teams may say "deployment frequency" or "we ship X times per day".
• Dε = Delivery error ratio. Quality teams may say "change fail rate" or "percentage of rollbacks".
• Rτ = Restore lead time. Site reliability engineers may say "time to restore service" or "mean time to restore (MTTR)".
Queueing theory
from joelparkerhenderson
