Generic Algorithms for Consistency Checking of Mutual-Exclusion and Binding Constraints in a Business Process Context

Abstract

In this paper, we present generic algorithms to ensure the consistency of mutual-exclusion and binding constraints in a business process context. We repeatedly identified the need for such generic algorithms in our real-world projects. Thus, the algorithms are a result of the experiences we gained in analyzing, designing, and implementing a number of corresponding software systems and tools. In particular, these algorithms check corresponding consistency requirements to prevent constraint conflicts and to ensure the design-time and runtime compliance of a process-related role-based access control (RBAC) model.

On the Impact of Concurrency for the Enforcement of Entailment Constraints in Process-driven SOAs

“…Mutual exclusion and binding constraints are typical examples of entailment constraints (see, e.g., [6,20,25,26]). …”

“…In a process-driven SOA, the respective process engine must ensure the consistency of process-related RBAC models (see, e.g., [11]). In particular, it must enforce the entailment constraints and ensure the static (design-time) and dynamic (runtime) correctness of the corresponding models to prevent constraint conflicts or inconsistencies (see, e.g., [19,20]). Figures 1 and 2 show a simplified example of a business process that is executed via a process-driven SOA.…”

“…In order to perform the different tasks, the subjects invoke corresponding software services. If, for instance, there is a subject-binding between t a and t f and a DME constraint between t a and t e (see Figure 2), the respective process engine must ensure that for each process instance p i , the corresponding task instances t ai and t fi are allocated to the same subject while the task instances t ai and t ei are allocated to different subjects (see, e.g., [19,20] …”

“…In the context of our work on the specification and enforcement of entailment constraints in business processes (see, e.g., [11,[19][20][21]), we implemented a corresponding runtime engine. Our runtime engine ensures the consistency of business processes with corresponding entailment constraints at the type-level (design-time) and at the instance-level (runtime).…”

“…For example, if the tasks t a and t e from Figure 4(b) are mutually exclusive, the choreography engine of domain y needs to know which subject was allocated to an instance of t a to correctly allocate instances of t e (see, e.g., [19,20] Figure 1. It illustrates the process flow and the message exchange that is necessary to allocate task instances at runtime.…”