Hi @Hashmit,

When you are setting up a meter its possible to define a start value. As you correctly pointed out in general cases the start value is zero. But by adding a start value system allows to set up a used meter for an equipment parameter and only consider the actual measurement value that was recorded for that particular object.

as an example. if you setup a used meter with a start value 100, and then record a measurement of 150. System will register the total value for the parameter for that object as 50. (this is for accumulated parameters)

you can refer to the documentation related to meter setup and measurements from 

https://docs.ifs.com/ifsclouddocs/24r1/EquipmentAdministration/ActivitySetupChangeMeter.htm?StandAlone=true

https://docs.ifs.com/ifsclouddocs/24r1/PMProcessing/AboutMeasurements.htm?StandAlone=true

https://docs.ifs.com/ifsclouddocs/24r1/ProcessModels/Process_Model/UpdateMeasurements.htm?StandAlone=true