Web Service Ecosystems Future Obstacles
written by gunther gerlach-2009
As seen through this section, web service ecosystems can generally be described as a logical collection of web services whose exposure and access are subject to constraints, which are characteristic of business service delivery. A lower level analogy can be found with application servers, where access and inter-operation of components is regulated by middleware functions such as discovery/brokering, remote access, object pooling, transactions, asynchronous messaging, persistence management, and so on.
For web service ecosystems, the regulation entails service delivery at the business level. Therefore, frameworks supporting web service ecosystems constrain the way services are discovered, authenticated, adapted and mediated, transacted, charged and paid for, monitored, penalized against breaches of use, fulfilled, and ranked. This is from the service demand side. From the supply side, regulations would be imposed on the way services are published, value-added or repurposed through composition with other services, re-provisioned through leasing and licensing, and independently brokered. The other fundamental difference with application servers is that the “middleware” comprises web services themselves that are potentially outsourced in the ecosystem. Thus, a variety of payment “engines” with specialization in particular payment methods could be registered so that they can be bound to instances of running services requiring particular payment functionality.
A service marketplace can then be seen as a specific, and currently prominent, example of a web service ecosystem. A “pan-marketplace,” spanning multiple marketplaces, as in multi-jurisdictional marketplace of government online services, is an extrapolation of this. General-purpose supply/value chaining, aka business service networks, is yet another example.
In summary, web service ecosystems trans-locate not so much web services, but web service delivery
– collectively making more explicit the notion of service procurement. Clearly, the extent to which services delivery is regulated is a moving target, and will develop as Internet business models grow in sophistication.
In the following sections, a number of critical aspects of service delivery are discussed to gauge current limitations of web service ecosystems. These are
• Service supply and distribution networks: the extent to which different service supply and distribution roles are supported;
• Service discovery and planning: the flexibility of capturing semantics of services in wider, domain non-specific ecosystems, and the flexibility of service discovery in this setting, including support of fuzzy search goals;
• Conversational service interactions: the extent to which service interactions go beyond basic request-to-execute transactions, in support of negotiations and long-running, multi-party service interactions;
• Service quality management: the extent to which non-functional properties are captured in service descriptions such that the quality of delivery can be managed in accordance to service level agreements;
• Service mediation and adaptation: the extent to which automated assistance is available to repurpose services in order to compose them and bind them to service delivery components in ways not foreseen when these services were originally designed.
Published by. BPTrends November 2005
