Criticisms of SOA

Criticisms of Service Oriented Architecture SOA

Some criticisms of Service Oriented Architecture SOA are based on the assumption that SOA is just another term for Web Services. For example, some critics claim SOA results in the addition of XML layers introducing XML parsing and composition. In the absence of native or binary forms of Remote Procedure Call (RPC) applications could run slower and require more processing power, increasing costs. Most implementations do incur these overheads, but Service Oriented Architecture SOA can be implemented using technologies (for example, Java Business Integration (JBI)) which do not depend on remote procedure calls or translation through XML. However, there are emerging and open-source XML parsing technolgies, such as VTD-XML, and various XML-compatible binary formats (http://vtd-xml.sf.net/persistence.html) that promise to significantly improve the Service Oriented Architecture SOA performance.

Stateful services require both the consumer and the provider to share the same consumer-specific context, which is either included in or referenced by messages exchanged between the provider and the consumer. The drawback of this constraint is that it could reduce the overall scalability of the service provider because it might need to remember the shared context for each consumer. It also increases the coupling between a service provider and a consumer and makes switching service providers more difficult.

Another concern is that WS-* standards and products are still evolving (e.g., transaction, security), and Service Oriented Architecture SOA can thus introduce new risks unless properly managed and estimated with additional budget and contingency for additional Proof of Concept work.

An informal survey by Network Computing placed Service Oriented Architecture SOA as the most despised buzzword (November 2006).

Some critics feel SOA is merely an obvious evolution of currently well-deployed architectures (open interfaces, etc).

A SOA being an architecture is the first stage of representing the system components that interconnect for the benefit of the business. At this level a SOA is just an evolution of an existing architecture and business functions. SOAs are normally associated with interconnecting back end transactional systems that are accessed via web services.

The real issue with any IT "architecture" is how one defines the information management model and operations around it that deal with information privacy, reflect the business's products and services, enable services to be delivered to the customers, allow for self care, preferences and entitlements and at the same time embrace identity management and agility. On this last point, system modification (agility) is a critical issue which is normally omitted from IT system design. Many systems, including Service Oriented Architecture SOAs, hard code the operations, goods and services of the organisation thus restricting their online service and business agility in the global market place.

Adopting SOAs is therefore just the first (diagrammatic) step in defining a real business system. The next step in the design process is the definition of a Service Delivery Platform (SDP) and its implementation. It is in the SDP design phase where one defines the business information models, identity management, products, content, devices, and the end user service characteristics, as well as how agile the system is so that it can deal with the evolution of the business and its customers.