6th European Conference - Academic Conferences

Maria Semmelrock-Picej et al.
In the case of a centralized collaboration only the hub company offers services which are accessed by
partners. The partner companies only act as identity provider for their federated users. This type of
collaboration mostly apperas when only one large company is involved which offers a large service
and application landscape with complex business processes supported by workflow management
systems and when partners are mostly smaller companies without an own service infrastructure but
specialized and/or cost-efficient employees which take over whole outsourced services of the Hub
company.
In the case of a decentralized collaboration (see figure 9) all partners offer services in the
collaboration and act as Service Providers which are accessed mutually. All Partner act as identity
Provider for their federated users. This type of collaboration often appears when one or more large
companies are involved which offer a large service and application landscape with complex business
processes supported by workflow management systems and those workflows include the involvement
of highly specialized partner companies or when partners are companies with few but highly
specialized services which can be offered cost-efficiently.
Figure 9: Decentralized collaboration
3.2.3 Role and resource management
Modeling roles is a research topic with a long history. There are a lot of approaches (Ferraiolo, Kuhn
and Chandramouli 2003) which are more or less successful. They can be classified according to three
different strategies:
Top-down is based on the analysis of business processes and organizational structures;
Bottom-up tries to analyze information of existing permissions throughout different systems and
aggregate similar patterns (clusters) to roles;
Hybrid approaches combine both strategies
The necessary steps during resource and role management are modelled in figure 10.
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