Ontology: Techno Order
Code:

A group of elements that have similar characteristics.

A first example. In object-oriented design, a layer is a group of classes that have the same set of link-time module dependencies to other modules. In other words, a layer is a group of reusable components that are reusable in similar circumstances. (Wikipedia: Layer (object-oriented design)).

A second example. The Shearing layers concept views buildings as a set of components that evolve in different timescales, from the site that is "eternal", to stuff that twitches around daily to monthly; (Wikipedia: Shearing layers).

A third example is elaborated in greater detail because of our interest in Enterprise Architecture. The ArchiMate Framework defines three main layers for modelling an enterprise (ArchiMate 2.1 Chapter 2.5 Layering), and a "layer extension" for modelling change.

In Archimate 3, strategy elements were added to the standard.

The core layers, and the strategy elements come with a number of concepts that cover these aspects:


Aspect Active structure aspect Behaviour aspect Passive structure aspect
Layer Interface + Actors (Subjects) Service, Process, Function, … Object
Strategy elements Capability, Course of Action Resource
Business Layer Business Interface + .. Business Service, Business Process, Business Function, … Business Object
Application Layer Application Interface + .. Application Service, Application Process, Application Function, … Data Object
Technology Layer Technology Interface + .. Technology Service, Technology Process, Technology Function, … Artifact

Finally Archimate contains an "aspect extension" Motivation Extension to model motivational concepts such as goal, Principle and requirement.

The layers defined by Federal Enterprise Architecture Framework differ somewhat from those of Archimate.


Layer in the tree of Techno Order (scope):