Upgrading Ensemble from 2015 to 2018

@Abhishek Raj - start with reviewing the documentation for new features, and Upgrade Compatibility checklists:

https://docs.intersystems.com/latest/csp/docbook/DocBook.UI.Page.cls?KEY...
This will be the most comprehensive collection of suggestions, things to know, and 'gotcha's' to be aware of.  

Beyond reading the docs and seeing what is applicable to your environment, do a practice upgrade of your application and TEST, TEST, TEST :)  

Lastly, make sure you review the supported platform list for 2018.1 and 2015.2:

2018.1: https://docs.intersystems.com/latest/csp/docbook/DocBook.UI.Page.cls?KEY...

2015.2: https://cedocs.intersystems.com/ens20152/csp/docbook/DocBook.UI.Page.cls...

Hope that helps!