Hi there,
Sorry for the delay, but after analyzing the scenario you described, I realized that a recommended approach that could be used for this kind of scenarios, could be like the one used in the UI Composition QuickStart provided with Prism , which so far is the only sample I know, that illustrates a similar scenario like the one you described.
As you may find this approach, could be useful to keep a clean separation on the different layers of your application. Also, it uses different view models for each of the details views in order to represent the information from the currently selected Exployee which for example in your case could be the selected customer , this approach in my opinion will result in a cleaner one than only having only one view model.
Although, this sample was built with Unity and Silverlight I believe you could find the concepts explained there useful to tackle your application as a similar approach could be used in a WPF application without problems.
I hope you find this as a helpful reference to start with,
Regards,
Agustin Adami
http://blogs.southworks.net/aadami
