When you upgrade your Portal to NW 7.3 or 7.4 and need new BPs and doesnt want to upgrade ECC ie from EHP4 to EHP6/7, Please check below note
BP ESS 1.41
BP MSS 1.41
Moving towards ESS WD ABAP from WD JAVA, would indeed be a reimplementation but customer can preserve their configuration in backend but not in portal if they choose to use new Iviews. If they want to run parallel both JAVA WD and ABAP WD Iviews it ll require two set of roles once they activate switches for ESS and MSS as listed in below notes and links.
All Business Switches are listed here and their Important documentaion ie what and which functionality each switch brings and also the roles.
Important Notes to consider :
1450179 ESS Based on Web Dynpro ABAP Available as of EHP5
1701634 HR renewal 1.0: Release Information Note
1685257 Portal Upload ie Business Package Deployment EHP6 above and beyond for WDA
EHP5 ESS (EA HR 605) Switch HCM_ESS_WDA_1Business Package for Employee Self-Service (WDA) 1.50 - SAP Library
EHP6 ESS (EA HR 606) HCM_ESS_WDA_2Business Package for Employee Self-Service (WDA) 1.50 - SAP Library
Support Package 10 = Feature Pack 3
Configuration Landing Page or SPB Configuration of Suite Page Builder (UI5)
HR renewal 2.0 is out HR Renewal 2.0 begins
You can check delta of functionality between different releases using the[ SAP Solution Browser SAP Solution Browser
For MSS we have something called MSS ADD ON
Check the help links here first to understand the functionality :SAP Library - Manager Self-Service (WDA)
POWL or UWL
POWL Inbox configurations for Manager Self-Service EhP5 and above
MSS POWL Inbox config (EHP5 & above) - LAUNCHPADHANDLER action
Muliple level approval configuration as of HR Renewal FP3 Configurations for enabling Multiple approvers for Leave Request
SAP Notes for customisaiton of Leave request and Working time approval
Fiori and HR Renewal
Fiori apps are designed to work on desktop, tablet and smartphones using the same code and based on SAPUI5.
SAP Fiori does not replace HCM UX renewal, which is an in-depth renovation across all HR processes. SAP Fiori focuses on simplification for the most broadly and frequently used business functions for enterprise users. Fiori includes HR apps, but has a broad scope, including not only employee and manager but also purchasing agent and sales reps. Fiori usage will require extra licensing cost as opposed to HR renewal.