Kanban guide · Lean foundations
What Is DevOps? Culture, Practices and Metrics
DevOps is a set of cultural values, practices and tools that bring software development and IT operations together, so teams can deliver changes quickly and reliably. It extends Agile and Lean thinking across the whole path from code to customer.
Key takeaways
- DevOps unites development and operations around shared goals.
- CALMS and the Three Ways summarise its principles.
- Measure it with deployment frequency, lead time, change failure rate and time to restore.
Origins
The term DevOps emerged around 2009, when Patrick Debois organised the first DevOpsDays conference in Ghent, Belgium. It grew from frustration with the wall between developers, who wanted change, and operations, who wanted stability.
The CALMS model
| Element | Meaning |
|---|---|
| Culture | Shared responsibility and collaboration between development and operations |
| Automation | Automate builds, tests, infrastructure and deployments |
| Lean | Small batches, limited WIP, focus on flow |
| Measurement | Measure flow, quality and user outcomes |
| Sharing | Share knowledge, tools and lessons learned |
The Three Ways
Popularised by The Phoenix Project and The DevOps Handbook:
- Flow: speed up the flow of work from development to operations to the customer.
- Feedback: create fast feedback from operations and users back to development.
- Continual learning and experimentation: build a culture that learns from failure and improves.
Key practices
- Continuous integration and continuous delivery.
- Infrastructure as code.
- Automated testing and monitoring.
- Small, frequent releases with feature flags.
- Teams that build and run their own services.
- Blameless post-incident reviews.
Measuring DevOps performance
The DORA research programme popularised four key measures of software delivery:
- Deployment frequency: how often you release.
- Lead time for changes: from commit to production.
- Change failure rate: share of releases causing problems.
- Time to restore service: how quickly you recover from failure.
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Frequently asked questions
Is DevOps a role or a culture?
Primarily a culture and set of practices. Many organisations also have "DevOps engineer" roles focused on automation and tooling.
How does DevOps relate to Kanban?
Both focus on flow, small batches and visibility. Many operations and platform teams use Kanban to manage their work.
What is DevOps in simple terms?
DevOps is a way of working that brings software development and IT operations together, so teams can build, release and run software faster and more reliably.
When did DevOps start?
The term emerged around 2009, when Patrick Debois organised the first DevOpsDays conference in Ghent, Belgium.
What does CALMS stand for in DevOps?
Culture, Automation, Lean, Measurement and Sharing: a model summarising the main elements of DevOps.
What are the four DORA metrics in DevOps?
Deployment frequency, lead time for changes, change failure rate and time to restore service. They measure both speed and stability of software delivery.
What are the Three Ways of DevOps?
Flow from development to operations, fast feedback in both directions, and a culture of continual learning and experimentation.
Is DevOps part of Agile?
DevOps extends Agile ideas beyond development into release and operations. Agile speeds up building software; DevOps speeds up getting it safely to users.
What is the difference between DevOps and continuous delivery?
Continuous delivery is a specific technical practice for keeping software releasable. DevOps is the broader culture and set of practices, of which continuous delivery is a key part; see continuous delivery.
What does a DevOps engineer do?
A DevOps engineer usually builds and maintains deployment pipelines, infrastructure automation and monitoring, helping development and operations teams work together.
What is a blameless post-incident review in DevOps?
A review after an outage that focuses on what in the system allowed the problem to happen, rather than who to blame, so people share information openly and the team learns.