A Schedule Variance Index ( SVI) threshold value is expressed as a ratio. An issue is generated if the Schedule Variance Index (the ratio of the schedule variance to the planned value) falls beyond the threshold values.
The Schedule Variance Index is calculated as SVI = Schedule Variance ( SV) / Planned Value Cost. A value less than 0 indicates that the value of the work performed is less than what was scheduled.
If the threshold value is 0, an issue is generated whenever the value of the work performed falls below the expected cost of performing that work, according to the schedule.