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title: “DORA - Median Time to Restore Service” description: > DORA - Median Time to Restore Service sidebar_position: 28

What is this metric?

The time to restore service after service incidents, rollbacks, or any type of production failure happened.

Why is it important?

This metric is essential to measure the disaster control capability of your team and the robustness of the software.

Which dashboard(s) does it exist in

DORA dashboard. See live demo.

How is it calculated?

MTTR = Total incident age (in hours)/number of incidents.

If you have three incidents that happened in the given data range, one lasting 1 hour, one lasting 2 hours and one lasting 3 hours. Your MTTR will be: (1 + 2 + 3) / 3 = 2 hours.

Below are the benchmarks for different development teams from Google‘s report. However, it’s difficult to tell which group a team falls into when the team's median time to restore service is between one week and six months. Therefore, DevLake provides its own benchmarks to address this problem:

Groups	Benchmarks	DevLake Benchmarks
Elite performers	Less than one hour	Less than one hour
High performers	Less one day	Less than one day
Medium performers	Between one day and one week	Between one day and one week
Low performers	More than six months	More than one week

Data Sources Required

This metric relies on:

• Deployments collected in one of the following ways:
  • Open APIs of Jenkins, GitLab, GitHub, etc.
  • Webhook for general CI tools.
  • Releases and PR/MRs from GitHub, GitLab APIs, etc.
• Incidents collected in one of the following ways:
  • Issue tracking tools such as Jira, TAPD, GitHub, etc.
  • Incident or Service Monitoring tools such as PagerDuty, ServiceNow, etc.

Transformation Rules Required

This metric relies on:

• Deployment configuration in Jenkins, GitLab or GitHub transformation rules to let DevLake know what CI builds/jobs can be regarded as Deployments.
• Incident configuration in Jira, GitHub or TAPD transformation rules to let DevLake know what CI builds/jobs can be regarded as Incidents.

SQL Queries

If you want to measure the monthly trend of the Median Time to Restore Service as the picture shown below, run the following SQL in Grafana.

-- Metric 3: median time to restore service - MTTR
with _incidents as (
-- get the number of incidents created each month
	SELECT
	  distinct i.id,
		date_format(i.created_date,'%y/%m') as month,
		cast(lead_time_minutes as signed) as lead_time_minutes
	FROM
		issues i
	  join board_issues bi on i.id = bi.issue_id
	  join boards b on bi.board_id = b.id
	  join project_mapping pm on b.id = pm.row_id and pm.`table` = 'boards'
	WHERE
	  pm.project_name in ($project)
		and i.type = 'INCIDENT'
		and i.lead_time_minutes is not null
),

_find_median_mttr_each_month_ranks as(
	SELECT *, percent_rank() over(PARTITION BY month order by lead_time_minutes) as ranks
	FROM _incidents
),

_mttr as(
	SELECT month, max(lead_time_minutes) as median_time_to_resolve
	FROM _find_median_mttr_each_month_ranks
	WHERE ranks <= 0.5
	GROUP BY month
)

SELECT
	cm.month,
	case
		when m.median_time_to_resolve is null then 0
		else m.median_time_to_resolve/60 end as median_time_to_resolve_in_hour
FROM
	calendar_months cm
	LEFT JOIN _mttr m on cm.month = m.month
  WHERE $__timeFilter(cm.month_timestamp)

If you want to measure in which category your team falls into as in the picture shown below, run the following SQL in Grafana.

with _incidents as (
-- get the incidents created within the selected time period in the top-right corner
	SELECT
	  distinct i.id,
		cast(lead_time_minutes as signed) as lead_time_minutes
	FROM
		issues i
	  join board_issues bi on i.id = bi.issue_id
	  join boards b on bi.board_id = b.id
	  join project_mapping pm on b.id = pm.row_id
	WHERE
	  pm.project_name in ($project)
		and i.type = 'INCIDENT'
		and $__timeFilter(i.created_date)
),

_median_mttr_ranks as(
	SELECT *, percent_rank() over(order by lead_time_minutes) as ranks
	FROM _incidents
),

_median_mttr as(
	SELECT max(lead_time_minutes) as median_time_to_resolve
	FROM _median_mttr_ranks
	WHERE ranks <= 0.5
)

SELECT
	case
		WHEN median_time_to_resolve < 60  then "Less than one hour"
    WHEN median_time_to_resolve < 24 * 60 then "Less than one Day"
    WHEN median_time_to_resolve < 7 * 24 * 60  then "Between one day and one week"
    WHEN median_time_to_resolve >= 7 * 24 * 60 then "More than one week"
    ELSE "N/A.Please check if you have collected deployments/incidents."
    END as median_time_to_resolve
FROM
	_median_mttr

How to improve?

• Use automated tools to quickly report failure
• Prioritize recovery when a failure happens
• Establish a go-to action plan to respond to failures immediately
• Reduce the deployment time for failure-fixing