While this can be a complicated question with many factors impacting the decision for each organization, there are a few initial questions that help determine if further consideration is warranted. Here are my top five:
- Will users be migrated over time or in a single batch? - For most organizations, migration truly is a process not an event. It would be too disruptive to operations and the users if they were all expected to start using Exchange/Outlook simultaneously. As a result, phased migrations are most common and introduce a greater need for users to collaborate across the two mail platforms.
- Do users schedule meetings with a variety of users and departments? - If meetings are scheduled across departments or even across the organizations, it becomes more difficult to coordinate simultaneous migrations and increases the value of seamless coexistence during the transition period.
- Does the organization rely on free/busy information when scheduling meetings? - The use of free/busy varies greatly between organizations and there almost seems to be a cultural aspect to usage levels within organizations. If an organization currently relies on free/busy information when scheduling meetings, losing that capability during a migration can be disruptive and impact the initial perception of the new mail platform. As a result, full coexistence becomes more important as free/busy usage increases.
- Will applications continue to run in Lotus Notes after the users are migrated to Exchange? - Even if applications will eventually be migrated, there is typically an interim period (which is commonly extended) where application workflows and functionality must be preserved and seamless for users in Exchange.
- Do users leverage native Notes encryption and other rich features available in Notes? - As the use of encryption, tabbed tables, links and other proprietary features of Notes increases, so too does the need for coexistence.
This is obviously not an exhaustive list of questions when analyzing the need for coexistence, but should provide a high-level understanding of the need for further analysis and help organizations start the process of determining the appropriate level of coexistence for their project.