What is the main business of your organization?
Are the applications you want to modernize a part of your core business?
What legacy development environments are in use (e.g. PowerBuilder, Delphi, Rally etc.) and what target environment do you want to have (e.g. .NET, Java)?
What are the names of your legacy applications?
How many man-years of development efforts were invested into the first major release of your applications?
For how long are the applications in maintenance after the first major release?
How many man-years of development efforts were invested into the maintenance?
How many developers support the application now?
How well is the application documented?
Why do you want to move from the current platform ( business and technological drivers )?