hi, Kelly
Ditigal transformation of the company functions requires a wide appraoch. But to make it simple one way can be scheting a map of company functions. Every big scale function can be handled within an app or module.
Some standart data can be set into one module/app that is called stamdata or master data.
If you work with multiple apps, you can use rest services/interfaces in order to connect your apps.
If you use one app then one module can be a main module where the app communicates with the client.
The other moldules can perform the secondary functions. For standat functions you can build standart modules and intall them to market place and then downlaod them to other apps. For example: Standart search functions, handeling documents e.g.
Use workflows for functions that include multiple phases. It can be better to keep all workflows in one app/module/folder or you can keep them according to their functions.
And one important issue is to define the roles. There will be bussines roles, project roles and module roles. It is fine if you check mendix docs. https://docs.mendix.com/refguide/user-roles/
If we think a school app as example module and folder naming can be like this:
Personel>
Theachers
Medewerkers
Students>
Registration
Progress
Documents
Lessons>
Lessons Overview
Locations Overview
Planning>
Plan Lessons
Assign teacher
Assign student
Maintain Exams
Finance
...
It is also better to go through these documents:
https://docs.mendix.com/refguide/dev-best-practices/