Hi Saket,
There are several ways to implement a solution.
This is just one of solutions.
App -> SMP -> Gateway -> ERP. - Gateway is central Hub.
App -> SMP -> ERP(Gateway is on ERP). - Gateway is embedded on ERP.
Steps:
+ Develop OData on ERP.
(You can develop OData on Gateway and make RFC call to backend. Performance may not good for calling RFC several times)
+ Activate the OData services on Gateway
+ Develop an app using UI5 and consume OData
+ Build app using Cordorva/Kapsel with SMP
+ Configure OData proxy on SMP
Getting Started with Kapsel - Part 1
Regards, Masa
SAP Customer Experience Group - CEG