Hello Sachin,
In this case I would suggest to start with the research of Key Success Factors, e.g. in your case how do you define merchandize productivity and what ways of improvement you see.
Indicators are the measurement tool, and they will certainly help to tell if you are on the right track if you have a plan of improvement.
I can also suggest for you to follow the steps of this KPI system in order to sort out all the ideas related to the measurement.