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GISI ADO Level study materials
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GISI ADO Level: Introduction to DevOps

GISI ADO Level · Work through your exam, one topic at a time.

All guide sections

Introduction to DevOps

Scope of this domain

The Introduction to DevOps domain tests whether you can describe DevOps as a socio-technical system rather than a toolchain: its roots in Agile and lean manufacturing, the CALMS framing, the Three Ways, value-stream thinking, and the four DORA delivery metrics. Expect questions that classify a practice, interpret a metric, or pick the intervention that actually removes a bottleneck.

Core rules and concepts

  • DevOps = Culture, Automation, Lean, Measurement, Sharing (CALMS). A pipeline alone is not DevOps.
  • The Three Ways: flow (left to right, small batches, WIP limits), feedback (right to left, fast detection), continual learning (blameless postmortems, experimentation).
  • DORA four keys: deployment frequency; lead time for changes (commit to production); change failure rate; time to restore service.
  • Deployment is not release: deployment makes a version run in an environment; release exposes it to users. Feature flags decouple the two.
  • Value-stream maps separate touch time from queue time; in most organisations queue time dominates.
  • Westrum culture types: pathological (power), bureaucratic (rules), generative (performance). Conway's Law: architecture mirrors communication structure.

Worked example

A team deploys monthly with a 21-day lead time, 30% change failure rate and 9-hour MTTR. The value stream shows 14 days waiting for a change advisory board and 5 days of manual regression testing. Reasoning: the CAB wait is queue time, not effort, so the highest-leverage fix is smaller batch sizes with trunk-based development plus automated regression, and risk-tiered approval for low-risk changes. Lead time and change failure rate should respond first; MTTR needs better observability before it moves.

Traps that cost marks

  • Defining DevOps as 'CI/CD tools'; exam answers reward culture and flow.
  • Reporting lead time as sprint length or as time from ticket creation.
  • Confusing MTTR with MTBF; MTTR is time to restore service.
  • Assuming more approvals increase safety; they usually increase batch size and risk.
  • Treating deploy and release as synonyms.