Never Merged Dev Day Ratio (NMR)
Never Merged Dev Day Ratio (NMR) measures the portion of engineering time spent on changes that never make it into any main or integration branch (such as “main” or “dev”). It highlights wasted effort on abandoned work or pull requests that stall indefinitely.
Calculation
NMR is typically reported weekly or per sprint based on minware’s dev day attribution model.
The metric is calculated as:
NMR = total dev days spent on never-merged code ÷ total dev days × 100
Goals
NMR helps teams identify when developers are spending time on work that is never delivered. It answers questions like:
- How much effort is wasted on abandoned pull requests?
- Are stalled or rejected features consuming significant developer capacity?
- Is the PR process agile and decisive or prone to stagnation?
A high NMR is a signal of lost effort and can indicate issues such as unclear scope, poor communication, or bottlenecks in review or product strategy. Low NMR indicates efficient delivery and clean code flow.
This metric often correlates with anti-patterns like Abandoned Pull Requests and Unclear Requirements Problem.
Variations
NMR may also be referred to as Abandoned Work Ratio or Unmerged Effort Ratio. Common segmentations include:
- By team or product area, to identify domains with frequent abandoned work
- By engineer, to discover individuals struggling with scope or alignment
- By feature type, such as spikes, experiments, or refactor branches
- By timeframe, to see if there are peaks in rejected work after milestones or releases
Tracking by category helps teams differentiate between exploratory prototypes (which may not merge intentionally) and lost efforts that represent delivery inefficiencies.
Limitations
NMR measures wasted effort but does not capture why code was never merged. Work may be legitimately abandoned for strategic reasons, not process failure. It also depends on accurate capture of dev day timing per change.
To contextualize NMR, pair it with:
| Complementary Metric | Why It’s Relevant |
|---|---|
| Pull Request Size | Large PRs are more likely to stall or be abandoned |
| Review Latency | Long delays may cause PRs to be closed or forgotten |
| Direct Main Commit Dev Day Ratio (DMR) | High DMR may correlate with bypassing failed PR workflows altogether |
Optimization
Reducing NMR encourages clearer scope definition, faster feedback, and disciplined delivery:
- Define intent before coding by holding short alignment sessions or writing lightweight specs. This aligns with Definition of Ready.
- Encourage quick decision points within PRs to either merge, iterate, or close without delay.
- Use regular PR reviews to reduce idle or abandoned branches. Adopt Code Review Standards to enforce follow-through.
- Educate on scope ownership so developers know when to pivot or pause work.
- Visualize abandonment trends to flag areas or individuals needing additional support.
A low NMR reflects a team that delivers cleanly and decisively. When NMR rises, it's time to inspect planning, feedback, and execution practices.
