Streaming data at a sensor is sensed and received. The streaming data includes a plurality of observations. For a current observation in the plurality of observations, a health of the current observation is determined. Based upon the health of the current observation, a penalty is determined. A Sensor Health Index (SHI) for the current observation is obtained by aggregating the penalty with at least one SHI of one or more previous observations from the plurality of observations. An alarm is selectively generated based upon the SHI of the current observation.