MVVM WPF INotifypropertychanged

I personally suggest to keep it in ViewModel(unless it is very important to use in model), so that you can reuse your Models in another applications. 

 

Here are few links, please go through these 

 

http://stackoverflow.com/questions/6922130/in-mvvm-model-should-the-model-implement-inotifypropertychanged-interface

 

http://stackoverflow.com/questions/772214/in-mvvm-should-the-viewmodel-or-model-implement-inotifypropertychanged

 

https://www.codeproject.com/Questions/829686/In-MVVM-should-the-ViewModel-or-Model-implement-IN