Several pundits have attempted to define the principles of Service-Oriented Architecture (SOA). Here is a summary of the SOA principles I have been propounding.
I shall try to expand and illustrate these in future posts.
|Service Ecosystem ||Business viability depends on delivering services into a broader service ecosystem. Thus the service economy drives the business (which drives further services, which ultimately drive technology.) |
|Service Economy ||Each service represents a unit of value. Services are regarded as intrinsically tradeable, and have both an exchange value and a use value. (Of course we may often choose not to exercise the option to trade services, for various reasons.) |
|Service Integrity ||Each service represents a meaningful 'whole' from the user-side as well as from the supply-side. Service coherence, reliability and 'wholeness' promotes broad and robust use/reuse.|
|Loose Coupling / |
|Open (typically asynchronous) connections between organizations, components and services. Interoperability between human activity and software services.|
|Differentiated Service ||Functionality, quality or cost vary with circumstances, including identity and context. This helps to generate requisite variety in the service ecosystem. |
|Multiple Provision ||Availability of alternative services or service implementations, biodiversity. This produces agile and robust systems, and also helps to generate requisite variety in the service ecosystem.|
|Complexity / Stratification ||Complex networks of services must be understood as systems of systems. Such systems are generally organized in layers: one layer acts as a platform of services for the layer above. |
|Distributed Intelligence ||Not only is functionality distributed across a network of services, but the intelligence governing this functionality is also distributed. Systems with distributed intelligence may be amenable to much more radical change than centralized ones.|
|Model-Based Management ||Using business models to drive all aspects of system/service management |
|Component-Based Business ||Loosely coupled networks of independent business components. |
|Emergent Order ||The service economy evolves into a continous network of value-adding services, through a series of structure-preserving transformations. |