Modelling With Archimate 1: One Service or Many

For my daily work I have been modelling architecture for one of our customers using the Archimate notation. As our understanding of how to model with Archimate matures we have come up with a number of patterns that we use to deal with certain situations. This is the first in a series of posts where I will either answer or ask a question relating to a problem we have run into.

Take the following situation: You are modelling an SOA service that has a number of operations. Do you:

1. Create a single application service component and model the operations as application functions or
2. Create one application service for each operation?

The answer is 2 and to explain why here is an example:

Multiple Application Services

Notice on the diagram that there are two application functions, one realizing two application services and one realizing one application service. These are the functional areas of your application. If you use application functions to represent service operations you lose these semantics. You lose the ability to group related services and show the functional structure of your application, which is the purpose of application functions.

Note: this post was prompted by a discussion on the LinkedIn Archimate Group.