The last decade has seen an expansive growth of Service Oriented Architecture (SOA) as the basis for software design across the board. There have been several studies conducted focusing on the technology advances relating to SOA, the superiority of the model and the potential benefits that arise from implementing SOA.
It is in that context that the study published in IEEE Computer Society by Haresh Luthria and Fethi A. Rabhi makes for a very interesting read. The study focusses its attention on real-life implementations of SOA and the actuals benefits realized from such adoption of the SOA model. The rigorous study looks at the perceptions of benefits and reasons for SOA adoption, and compares them to the perceptions of the benefits that resulted from the SOA implementation. This is very different from what we have typically seen published regarding SOA, which is an echo-chamber of glowing one-sided praise of all the benefits of SOA without a level headed evaluation of actual benefits raised.
Before we dig deep into the finding of the study, let’s quickly recap what SOA means and what are the benefits typically associated with them. Services are discrete business functions that could be consumed by one or more sets of users within an organization. SOA is meant to facilitate the provision and consumption of such services in a seamless and interoperable manner without limitation to how, when and where they occur. Web Services is widely the technology chosen in implementing the SOA.
Commonly touted benefits of SOA include better definition and visibility of business flows, plug-and-play infrastructure, ability to leverage legacy systems across the enterprise, rapid development and reduced costs.
It is very interesting to note that the authors note that several participants in the study could not clearly articulate what SOA meant. This is not surprising given the amount of hype surrounding SOA, but not many will admit that there is not much clarity in the minds of many decision makers and some practitioners of SOA before choosing to implement SOA. Senior executives thought of services represented what the company offered to its customers and technologists assumed web services to be synonymous with being service oriented. Neither is true but a very common misconception as the study found.
The authors used a qualitative case study approach identifying key decision-makers in 15 organizations and interviewing them in a semi-structured fashion. The study included a broad set of questions dealing with implementation details, challenges and concerns, benefits realized and lessons learned. The study included 3 participants that had failed in the implementation of SOA.
The study finds that while mapping the business flows is crucial to the success of SOA, the tools available for Business Process Modeling (BPM) are at best incomplete making the process of coming up with the technical requirements manual and tedious. Plug and Play might be supported by SOA in theory but lack of SOA standards, impracticality of braking up services spanning multiple domains which led to ownership issues. Leveraging legacy systems is easier said than done as it takes time and effort to create a wrapper around legacy systems or re-write legacy systems into web services. The major benefit promised by SOA is service reuse leading to cost reduction and helping with rapid development. The study found that for various reasons reuse of services was low and riddled with risks and problems.
The study provides unique insights into practical challenges in SOA implementations but also what the practitioners feel are needed to make SOA implementations successful. This includes a Service Ecosystem consisting of partner organizations, better process modeling tools, rigorous governance and better SOA awareness and training.
This study is an important step in the evolution of SOA and we hope there are more studies
in this vein analyzing the practical issues facing the SOA implementations and a realistic view of its benefits instead of the singularly optimistic view of SOA presented by most material published on this topic.