Code review

Approval bottleneck

Also known as Required approval bottleneck, Approval gate bottleneck

By WeavePublished 2 min read

Definition

An approval bottleneck occurs when a required reviewer or approval rule constrains the flow of otherwise ready changes.

What the measure captures

An approval bottleneck occurs when a required reviewer or approval rule constrains the flow of otherwise ready changes. It is most useful when the team states the unit of analysis, the start event, the completion event, and the population being measured. A review request, a pull request, and a merge are related events, but they are not interchangeable. Keeping those boundaries visible prevents a dashboard from turning an operational signal into an unexplained score.

A practical example

If a compliance owner is the only approver for several teams, queue age and arrival rate can show why otherwise small changes wait. Start with a small sample and inspect the underlying requests before creating a target. Record the repository, change type, reviewer path, and relevant policy state. That makes it possible to explain an unusual result instead of simply celebrating or escalating a number. Compare similar work over time and annotate major changes in ownership, branch rules, or automation.

How to use it carefully

The answer may be clearer ownership, a backup reviewer, or risk-based policy. Removing the approval without understanding its purpose can increase exposure. Review metrics work best as prompts for team-level investigation. Combine them with review samples, author and reviewer feedback, escaped defects, rework, and delivery outcomes. Avoid ranking individuals from a single measure because review difficulty, system familiarity, and assignment patterns vary. A healthy process makes useful feedback available at an appropriate time while preserving accountability for the final change.

How this relates to Weave

Weave can connect review events with change context and delivery signals so teams can inspect approval bottleneck alongside review time, pull request size, and flow. That context helps teams investigate queues and quality patterns without treating one review number as a verdict on an engineer.

How this relates to Weave

Weave can connect review events with change context and delivery signals so teams can inspect approval bottleneck alongside review time, pull request size, and flow. That context helps teams investigate queues and quality patterns without treating one review number as a verdict on an engineer.

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Sources and further reading

  1. Managing protected branches, GitHub Docs