Article Preview
TopIntroduction
Recently, there has been much interest in forming on-demand dynamic collaborations between multiple companies, who although competitors, wish to collaborate on occasion because of some mutual business interest (Yamazaki, 2004). For example, in the e-Research domain, a number of research institutes may formulate a joint project to solve a challenging scientific problem that is outside the capabilities of a single organization to solve. This project, as an example, requires the institutes to form a dynamic collaboration that lasts only for the duration of the project. Within this project and collaboration, each institution contributes its own unique resources to the collaboration that enable a platform for researchers towards finding the solution for the problem (Jrotka et al., 2006).
The idea of dynamic collaborations in this way, however, is not new. For example, the area of virtual organizations (Mowshowitz, 1994; Foster et al., 2001; Globus, 2011; King, 1991) explores mechanisms that enable entities from different organizations to collectively create a virtual enterprise for some mutual benefit. This goal is typically achieved through open service discovery, negotiation and execution based on Service Level Agreements (SLAs). In particular, the Grid computing community has made some important research contributions to the Virtual Organization (VO) literature (Foster et al., 2001). The Grid computing model for virtual organizations is based on resources that are usually intended to be “persistent”, i.e., open to discovery via the Internet in an open pool, and are expected to be available to an open pool of users on an ongoing basis for as long as required (Globus, 2011). While specific resources of the infrastructure (e.g., computational elements, storage systems, instruments and tele-Collaboration sites, etc.) may be taken offline or added on a dynamic basis, the resources (drawn from the pool) as a whole should remain available for as much as possible.
In contrast to the virtual organization model just described, there is a growing trend where virtual enterprises, built around their own transient business interests require their contributed resources to remain hidden from outside parties (Phillips et al., 2002; Handley et al., 2002). Resources are only revealed to a select group of participants. One example of this is the policy-based provisioning of resources, where resources are revealed only to trusted, collaborating partners by the agreed upon policies defined for the resources (Tsai et al., 2007). In situations such as this, open service discovery mechanisms cannot be used, as this resource information is deliberately hidden. Collaborations built around this concept are termed dynamic collaborations.
One of the key features of a dynamic collaboration is an on-demand contribution of resources from participating autonomous organizations. To establish such dynamic collaborations, all participants involved in the collaboration require a standard way to specify and/or agree: (a) what resources are required (Requirements); (b) who will contribute resources (Contributions); (c) how to access these resources (Access Polices). The participants may also have to explicitly add the corresponding terms and conditions to the technical specifications. Furthermore, contributed resources residing in different autonomous organizations bring a problem of interoperability between them, not the least of which includes differing access policies.