The bottom line, however, is that some applications are simple and predictable, so migrating them using predefined mapping and the right tool will be a simple job. Others may be complex and custom enough to require significant development effort to rebuild them in SharePoint. Be careful not to confuse application design complexity with data complexity. A good data migration tool will handle all your data migration needs regardless of the level of development required, and should work equally well migrating content to custom SharePoint lists, web part pages, Infopath documents, Word documents, or Adobe Acrobat (PDF) documents.
As you plan the migration of a large Notes environment to the Microsoft platform, remember that some of your applications will not necessarily go to SharePoint. While most can be migrated, a large organization may decide that some of its applications need to go elsewhere. The primary alternative to SharePoint is a classic .NET application using SQL Server as the backend data store. The main reasons for choosing this option are the need to support very high volumes of data, and the need for relational database capabilities.
An organization also may use an off-the-shelf application like Microsoft CRM, BizTalk, Project Server, or other third party product. Survey your environment for such applications before you start your migration project, because they can be perfect homes for migrated applications. The organization also may have applications that no longer are active, but contain important legacy information that must be archived before the applications are terminated. You probably won't migrate the functionality of these applications, but, you may decide to archive the content in a SharePoint record retention site, or convert it to a useful format such as Word, PDF, MIME or plain text in a searchable SharePoint document library.
Finally, you may decide to leave certain applications running on Notes and Domino for the foreseeable future. These may be too expensive to move, rely heavily on unique Notes capabilities, or will soon die a natural death and aren't worth the trouble of moving.
SharePoint may not be completely out of the picture for applications that won't be migrated. Even if they are housed elsewhere, you can still surface these applications in the SharePoint user interface. A compelling aspect of SharePoint is its ability to be a portal-a single place for everyone to access all of their applications. A variety of SharePoint technologies and third party products are available to help you make external applications appear to be part of SharePoint.
Game Changers: Consolidation, Reuse, Automation
Large Notes-to-SharePoint migrations are costly, time-consuming and not without risk. All of this can be greatly reduced, however, by consolidating similar applications. Consolidation, in turn, leads to the ability to reuse your design, development, testing, and migration work. Automation will further simplify a large-scale migration project.
Consolidation allows you to turn many similar problems into just one. For example, your organization may have a custom Notes application that allows product teams to keep track of customer-reported feature requests and product defects. Over time, this application has been copied to applications used by other product teams, and you now have a dozen of them scattered throughout the organization. If you don't recognize that each of these applications is similar, you may inflate your cost by treating each one as a separate migration job. Even in the initial planning phase, failure to consolidate similar application designs can bloat your cost estimates and delay a project, or kill it altogether.