docs/Metrics/PRCycleTime.md

---
title: "PR Cycle Time"
description: >
  PR Cycle Time
sidebar_position: 14
---

## What is this metric? 
PR Cycle Time is the sum of PR Coding Time, PR Time-to-Merge and PR Deploy Time. It is the total time from the first commit to when the PR is deployed.

The reason why we use PR Time-to-Merge rather than PR Pickup Time + PR Review Time is that a merged PR may not have any review. In this case, PR Pickup Time and PR Review Time will be NULL, while PR Time-to-Merge is not.

## Why is it important?
PR Cycle Time indicates the overall velocity of the delivery progress in terms of PR. 

## Which dashboard(s) does it exist in?
- [Engineering Throughput and Cycle Time](/livedemo/EngineeringLeads/EngineeringThroughputAndCycleTime)
- [Engineering Throughput and Cycle Time - Team View](/livedemo/EngineeringLeads/EngineeringThroughputAndCycleTimeTeamView)


## How is it calculated?
You can define `deployment` based on your actual practice. For a full list of `deployment`'s definitions that DevLake support, please refer to [Deployment Frequency](/docs/Metrics/DeploymentFrequency.md).

<b>Data Sources Required</b>

This metric relies on PRs/MRs collected from GitHub, GitLab, BitBucket, Gitee or other code review tools.

<b>Data Transformation Required</b>

N/A

<b>SQL Queries</b>

The following SQL shows how to find the `cycle time` of a specific PR. DevLake pre-calculates the metric and stores it in table.project_pr_metrics.

```
SELECT
  pr_cycle_time/60 as 'PR Cycle Time(h)'
FROM
  project_pr_metrics
```


If you want to measure the monthly trend of `PR cycle time` in the screenshot below, please run the following SQL in Grafana. 

![](/img/Metrics/pr-cycle-time-monthly.png)

```
SELECT 
  DATE_ADD(date(pr.created_date), INTERVAL -DAY(date(pr.created_date))+1 DAY) as time,
  avg(ppm.pr_cycle_time)/60 as 'PR Cycle Time(h)'
FROM 
  pull_requests pr
  JOIN project_pr_metrics ppm ON pr.id = ppm.id
GROUP BY 1
ORDER BY 1
```


## How to improve?
1. Divide coding tasks into workable and manageable pieces;
2. Use DevLake's dashboards to monitor your delivery progress;
3. Have a habit to check for hanging PRs regularly;
4. Set up alerts for your communication tools (e.g. Slack, Lark) when new PRs are issued;
2. Use automated tests for the initial work;
5. Reduce PR size;
6. Analyze the causes for long reviews.