Dear Niraj
using output variants is in most cases on quite good option (and you can learn from them by checking how SAP has done itby analyzing the ABAP code as delivered; and some of the SAP default output variants are quite nice as "copy" functions). Check e.g: SAP EHS Management for Beginners
Please answer this question:
1.) are you looking for a long erm solution which is useful for end user (or is it more on "tech" level)?
Here a list of alternative options:
a) ALE
b.) Standard EHS export
Honestly in most cases "output variant" is the best option (if the tool/solution should be "end user" enabled). You can export the data in XLS, XML, or whatever kind of format or structure.
Using SAP approach via ALE in combination with XI/PI you will get the same results. On top you could try to use "EHS extractors" (which are available for SAP BW use) or you can generate your own extractors
Experience has shown that if you do not understand the APIs/BAPIs and EHS data model you are "lost". But you can be "happy". There are some example reports for use of BAPIs/APIs delivered by SAP. Check SAP EHS Management for Beginners and references therein. As an example: SAP EHS-BAPI_BUS1077_CREATE
C.B.