Mean Time Between Failure for an application

Hi Jeyeline  - you need to determine the average time between the resolution of one incident and the creation of the next incident.

create a calculated column for difference time

Time Between Failures =
DATEDIFF(
'Incidents'[Resolved on],
CALCULATE(
MIN('Incidents'[Created on]),
FILTER(
'Incidents',
'Incidents'[Created on] > EARLIER('Incidents'[Resolved on])
)
),
DAY
)

Once you have the Time Between Failures column, create a measure to calculate the MTBF by averaging these time differences.

MTBF =
AVERAGE('Incidents'[Time Between Failures])

Few reference links:

Maintenance KPI - Calculating MTBF & MDT (Mean Time Between Failures & Mean Downtime) in Power BI

Maintenance KPI – Calculating MTBF & MDT (Mean Time Between Failures & Mean Downtime) in Power BI - Effective Dashboards

Jeyeline See my article on Mean Time Between Failure (MTBF) which uses EARLIER: http://community.powerbi.com/t5/Community-Blog/Mean-Time-Between-Failure-MTBF-and-Power-BI/ba-p/339586.
The basic pattern is:
Column = 
  VAR __Current = [Value]
  VAR __PreviousDate = MAXX(FILTER('Table','Table'[Date] < EARLIER('Table'[Date])),[Date])

  VAR __Previous = MAXX(FILTER('Table',[Date]=__PreviousDate),[Value])
RETURN
 ( __Current - __Previous ) * 1.