What is a Service?

So, what is a Service really? Can a chair be a Service? Or does a Service require some active part?

During the discussions in the PESOS workshop, we found now exact answer to that question, however, there seemed to be an agreement on one thing: a Service needs a provider that offers the Service to some Customer. But, you might add, a chair can be considered as a Service provider because the Service that is provided is the ability for a someone to sit on it. This is of course true, but a chair is not an active entity. It can be used for the provision of the "Sitting-Service" and thus it plays no active role. Furthermore, a Service is found during a discovery process and thus a description of the Service is needed. A chair per se offers no Service description of itself and thus cannot be discovered "directly". Consequently we need someone that tells us that the chair can be used for the "Sitting-Service" and we need to contact this "Sitting-Service" provider and ask for the chair.

In theory, one can argue more or less "forever", and can always find an example that is a Service for one person while another person does not agree on that. These discussion resemble a bit the disagreements about objects (after all: what is an object?) when object orientation became popular. However, nowadays, we take objects for granted (at least most of us) and will maybe do the same with Services in the (near?) future.

- Martin Treiber