Layering as an abstraction

Layering is a way to structure value models to show what value is added to a base layer. This is an abstraction. It omits information about the value networks. Lower layers do provide services to higher layers, but when we look closer, we may also find that higher layers provide some services to lower layers. For example, Samsung uses Facebook for advertising, even though at the same time Facebook runs on Samsung machines.

The abstractions we make in a model are guided by our modeling goal. Any given layer diagram expresses what we want to say about a hierarchy of service provision and omits other things. The Android hierarchy expresses a hierarchical relation between the primary offerings of some actors in the smartphone ecosystem. If we had wanted to express the role of Meta, the company that provides the Facebook app,  in the advertising ecosystem, we would have ended up with a different diagram.