There are 4 parts to a typical Notes to SharePoint migration project, they are:
a. User account migration
b. Data migration
c. Application migration
d. Mail Box migration
Out of all the above parts, Application migration requires a huge amount of skill and effort specially when you rely on Visual Studio's Windows Workflow Foundation (WWF) for your workflow development, on the other hand if you have Nintex workflows your job becomes much more easier.
I am heavily into Application migration one because it is challenging and secondly it helps you understand the nature of the business processes that different companies follow.
Based on my day-to-day experiences with Application migration, I have prepared a Drill Down Application migration estimation template which captures all the key parameters that will help you develop a near perfect estimate.
Click here to download the Lotus Notes to SharePoint Application Migration Drill Down Estimation template
Once the estimation is in place, half the battle is won and success is close by. But overall success of a migration project also depends heavily on technical skills that your team posses, effective planning, resource mobilization, risk management and client communication.
I personally believe team members and tech leads need to be given good solid technical trainings before they actually start a migration project. Especially when you use some third party tool for Data migration like Quest Notes Migrator for SharePoint or Nintex workflows for Application migration, Microsoft InfoPath for business process forms. These tools have their own strengths and limitations, understanding both will help you play in a more safer zone and avoid conflicts and mismatch in the requirements, because lets face it, everything that you can do with Notes cannot be done in the same way in SharePoint and the vice versa. So a healthy relationship with the client and effective communication will help you save tons of hours of rework and change requests.
Do let me know, in case you have any comments or feedback on the template