Some customers are very interested on any information related to Office 2013 migration. What you will need to consider is first to identify the critical Office applications (Macros, Add-Ins) in your organisation. There are also some applications which consume Office products such Word or Excel. In any case, you will need to run some scenarios on a platform using Office 2013 and check any compatbility issues.
After, there are some applications you don’t know, not critical for the company but critical for the end-user. For that, why don’t you create a global survey ? Ask also the end-users to put their files in a shared directory, so you can analyse them. The complexity to migrate an Office application (uisng VBA code or a .NET Addin) depends on the number of code lines. Try to identify the complexity by doing a code review. After, we have some useful articles to help you:
- Guide Office 2013 Migration
Office 2013 compatibility guide http://technet.microsoft.com/en-us/library/ee819096.aspx
- A list of high-level technical changes: Changes in Office 2013 http://technet.microsoft.com/en-us/library/cc178954.aspx>
- More technical details:
Compatibility issues in Office 2013 http://msdn.microsoft.com/en-us/library/office/jj229903(v=office.15)