App-Like Files Defined

What is an application? What is a file? What do you call something that behaves like an app, but is an Office file? Most organizations have these types of Office files.  They are often very large, complex reporting Microsoft Excel files with heavy amounts of VB code wrapped in and around the file, customized to meet the needs of a particular business unit or even an individual.  They could also be Microsoft Access database files.  Think Orange County Choppers meets Microsoft Office.  These files are purpose built and almost always deemed as mission critical.    Sometimes the complexity alone doesn’t make them mission critical, but the fact they are so widely used within an organization.  Do you have these types of files in your organization?  What’s your plan for these files during an Office upgrade?