Subject: RE: RE: [soa-rm] about PoSO and Microservices
Question 1. If the issue is the literal difference between architecture vs architecture implementation, IMO this is the same question as: abstract class vs concreate class; virtual method vs implemented method. Abstract and virtual are signatures with no real, concrete implementation. An architecture starts abstract, describing types of entities, but listing no actual entity. Once you place an actual, real physical components in the architecture it becomes an implementation.
Question 2. The boundaries of SOA and categories of entities included within SOA (the extension of the SOA concept) speaks to how we define the concept of SOA. I continue to be surprised how difficult and technical it is to define an seemingly simple concept. Defining types and variations of SOA will be a significant exercise.
I cannot immediately answer the SOA boundary question. I can suggest a methodology which will produce an answer. I rely upon ISO standards in Data Harmonization and Terminology. To begin with ISO 704:2009(E) Terminology Work – Principles and Methods, Concepts have properties. For analysis of a concept, the properties are abstracted to characteristics. The purpose of the abstraction is to identify common features in a set of properties. For example, given the concept of a mouse. Mouse1 has the property of 1 button, Mouse2 has the property of 2 buttons. The abstracted characteristic is a mouse has one or more buttons. Similar concepts have shared characteristics, delimiting characteristics differentiates concepts. Identification of the concept’s unique combination of characteristics helps defines the concept and situates the concept within a network of related concepts. The set of characteristics that form a concept is the intension of the concept. The set of objects included within the concept is the extension. Necessary characteristics are true for all objects in the extension of the concept. A sufficient characteristic may not be true of all objects in the extension, but any object that has a sufficient characteristic is within the extension. For example, the concept woman has numerous characteristics. Not all women have given birth. However, being human and having given birth are sufficient characteristics to belong within the extension of the concept woman. Essential characteristics are both necessary and sufficient.