It is kind of common now to associate SOA with Service Reuse. Yes – reuse is a very good thing – why spend much more money and time if you can reuse. If a service is reusable, in addition to contributing to business agility, it is also “green service” – environment friendly as well. The question is – How exactly is service reuse achieved? Many have been disappointed by the results they see in their SOA initiatives because their primary measure (metrics) for their initiative is Reuse. They lack clear understanding of what the service reuse is and how to get there. They assumed that service reuse is a given thing once you initiate SOA. The reality speaks different language from the assumptions. I used to preach to my team service reuse is one of the primary goal and want the team to deliver reusable service from the start. Overtime, I tracked the services deployed and only few services had the potential for reuse. Why? – I tried to find reasons why Service reuse is such a very good thing but wrapped by illusion.

Some of the reasons I listed include: Service interface and data not propoerly designed, service components not well designed, service level not properly incorporated, requirements not understood creating issue with service granularity and functional limitation, etc… You know what? … these and many more could be a reason to the problem. But, is that really a problem? Can one avoid these pitfalls by doing everything perfect and achieve the service reuse needed? The answer is NO! Yes, for simple cases where you can do perfectly and get reusable service – say across multi-business domains or multi-channels. For large organizations with many lines of businesses (or domains) it is not easy to get reusable services for cross business domain reuse. I came to understand why Service Reuse is such an illusion in many cases and what the organizations have to do to achieve reuse.

Here is my learning in the field -

1. First recognize that achieving (or getting to) service reuse in SOA is a process – i.e. a service may have to go through some iterative cycles to be close to perfect for reuse across multi-channel and multi-business-domain. It is proved to be hard to arrive at reusable service by just one shot! For large enterprise, this is mainly because of the lack of proper understanding of the complete requirements across the lines of businesses. This is the case today as the projects are mainly driven by lines of businesses bounded by cost and time. You may argue that enterprise can invest in completing cross business requirement understanding and absorb the cost for making service reusable. If so, you may have to add a “market factor” to this – the business line has urgent need to enhance its business capability to meet customers’ demand and cannot wait horizontal enterprise requirement analysis.
2. Second, recognize the importance of good service design to achieve enterprise service reuse. The evolution of your service towards reuse ( or in other words, your path and speed to reusable service) depends on the quality of your initial service design. Taking the #1 above into consideration, if your service design is not done well to position for further evolution of the service for reuse, you will have to redesign the service or end-up with duplicate non-reusable services across the enterprise – defeating the overtime “green service” vision of SOA.
3. Third, understand that enterprise service reuse requires strong SOA governance to facilitate the service reuse process. This goes into Service portfolio and service life-cycle management for the enterprise and more…
4. Fourth, recognize that SOA infrastructure can play a major role in facilitating enterprise service reuse … more on this in my next blog postings

I will try to share some detail toughts on this later… Bye for now.