History repair which damage code, cause code and failure code is very important for us especially for Maintenance people but how to calculate cost saving vs EAM if we keep the history.
Does anyone in the Group/this forum have experience or tell me how to calculate or any formula to calculate?

The history gives you information on effort and costs on an equipment.
When you have to repair this equipment you will (hopefully) know the planned costs and together with the knowledge about the asset value this will help to decide whether to repair or to rebuild.

It will not automatically come from the damage, cause and failure code.

M.Salman, it sounds like you are trying to justify for a CMMS? Betul, pak? Why use CMMS and not the paper-based system? Well, Bill gates says business will be done at the speed of light if we use computers. The work order management, spare parts management and data analysis for KPIs will be faster and easier done, etc.