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Application Migration vs. XPage enablement


In a recent customer discussion a claim was made: " If Notes client application don't automagically can be converted into XPages applications, then we very well can migrate to another platform, it is just the same". An interesting claim, I'll subject it to a reality check. In any case it is a good idea to revisit your investment in your existing applications first.

XPages Enablement

Gradual availability of new functions
  • A reasonable estimate for the required effort is up to 30% of the initial effort. It very much depends on the quality of the existing applications and familiarity and skills of your team
  • There is no data migration, so existing users using a Notes client can continue to use the application until you retire the Notes clients
  • You can look at your application from a functionality and user perspective. A typical first XPages application is an approval module that spans across all your existing applications and provides a single view into anything that needs approval. A next level is forms and tools for mobile personell
  • Domino's security model works in XPages too, so no changes are required
  • If a function in an XPage shows a bug, it doesn't stop executing the function, since a user can fall back to a Notes client until the bug is fixed
  • Mail notifications just work, it's Domino. Also you can build Attention Central
So in a nutshell: low risk, incremental availability, no data migration, freedom to innovate

Application Migration

Big bang migration of applications
  • Your investment in rewriting applications probably will be the same or more of the initial investment - that's why you did the CoCoMo analysis in the first place
  • Data needs to be migrated, so at some point in time you have a hard cut-over. Shut down (or put to read-only) the existing app and start using the new application
  • Before releasing the new application it needs to be feature complete including reports, admin UI, data management. Quite often the time doubles from core feature complete to all features - delays and costs increase
  • Since applications need to be feature complete (!), you will need to pick an application by application approach. This makes simplification and synergy effects more difficult
  • A bug can be a show stopper for the affected function since there is no fallback to the existing application
  • You need to build your own notification mechanism and eMail interface
  • When migrating data from Domino's NoSQL to an RDBMS, you might be in for complexity especially around access control. Complexity equals risk
Of course YMMV

Posted by on 01 December 2014 | Comments (3) | categories: XPages

Comments

  1. posted by Patrick Kwinten on Tuesday 02 December 2014 AD:
    I experienced a reverse 70/30 rule

    Initially it was promised that 70% of existing apps could be migrated WITH EASE with standard solutions in the other platform. The remaining 30% could be migrated within 2 years time.

    After signing the contracts it turned out that real estimations where that only 30% of the applications could be migrated "with ease" (read: notes document stored as pdf's without their attachments) and the remaining 70% could be migrated within 10 years.

    and still no CIO complaining...

    in stead of a reality check I would rather opt for a sanity check Emoticon undecided.gif
  2. posted by Stephan H. Wissel on Friday 05 December 2014 AD:
    @Lothar: if your server is Windows (jikes), you could get away with the DLLs (there's JNI) and the COM+ in XPages. A real show stopper is OLE inside of documents. ODBC should live on the server anyway (DECS anybody).

    It ain't easy, but that's why you called us(TM) Emoticon biggrin.gif
  3. posted by Lothar Mueller on Friday 05 December 2014 AD:
    Stephan,
    thankds once more for some good points. You know that I'd love to agree, and in quite some cases I can. But let's face the fact that there is this set of complex and long-running applications being tightly woven into the Notes client (extensive use of LS UI class functionality) and / or the Windows platform (using COM+, ODBC, platform and custom DLLs, to name just a few)."Webifying" those using Xpages can be a tedious and expensive task, could even justify a complete re-design. Unfortunately those applications often are the core ones in an enterprise. Not a real matchpoint in those dreaded "it's time to drop Domino" discussions, I'm afraid.