Mastering Continuous Delivery: Principles, Practices, and Metrics

Concept

Continuous delivery ensures that code can be deployed to production quickly and safely by submitting each change to a simulated production environment and using rigorous automated testing to verify that business applications and services meet expectations.

Goal

Frequent, fast, and stable product delivery.

Principles

Delivered versions can be deployed to production at any time.

Artifacts deployed to each environment must remain consistent.

The continuous delivery process should be visible to the team.

Prerequisites

Automation for integration, testing, and environment management.

Appropriate tooling to support the process.

Metrics to measure and enable closed‑loop continuous improvement.

Standards

Artifacts must originate from a unified corporate artifact repository.

Deployment results must be instantly notified to team members.

Artifacts must include both deployment and rollback components: code, configuration items, and database scripts.

Only artifacts that have passed regression testing, security scanning, change audit, and other automated or manual steps may be deployed to production.

Artifacts deployed to production must be version‑tagged.

After each deployment from the UAT environment, at least one smoke test must be executed.

For non‑production environments, it is recommended to automatically run regression tests after deployment.

Each environment must display the currently running application version.

Production deployments must have an associated change request.

Recommended Practices

Compile once, deploy everywhere – select artifacts and environments for deployment rather than starting from integration each time.

Separate code from configuration; manage configuration per environment and retrieve it at runtime from a configuration center.

Execute smoke tests immediately after deployment and clean up test data as appropriate.

Script both change and rollback procedures, including configuration and database rollbacks.

Rollback on any step failure.

Metrics

Number of successful (or rolled‑back) deliveries to UAT per week/month.

Number of successful (or rolled‑back) deliveries to production per week/month.

Average recovery time for failed changes.

Change in the number of ITSM tickets per release.