One important use case for (business) process technology is process compliance. We propose that managing security objects such as cryptographic keys is an application domain that can greatly benefit from using process technology because of a critical compliance requirement. To this end, we present a BPMN extension and a design of a support system for key management processes. Both were driven by a case study on a distributed application using a standard hierarchical public key infrastructure, which we also present. Our prototypical implementation of the support system shows that process compliance for security object management processes can be substantially supported with moderate effort by extending the standard process technology.

The Object Management Group maintains two notations to model business processes, BPMN and CMMN. While the two follow different approaches, both offer structures to model flexible processes or parts thereof. This gives rise to the question which standard should be chosen to adequately model such processes. We compare BPMN with a focus on its ad-hoc sub-process with elements of CMMN case models along a practical case study. While BPMN offers a certain degree of flexibility, CMMN has several benefits but also drawbacks. We discuss advantages and disadvantages of both notations. To answer the question of which notation to use for modeling flexible processes, we derive simple guidelines to help in making an informed choice.

The analysis of workflows in terms of structural correctness is important for ensuring the quality of workflow models. Typically, this analysis is only one step in a larger development process, followed by further transformation steps that lead from high-level models to more refined models until the workflow can finally be deployed on the underlying workflow engine of the production system. For practical and scalable applications, both analysis and transformation of workflows must be integrated to allow incremental changes of larger workflows. In this paper, we introduce the concept of a region tree (RT) for workflow models that can be used as the central data structure for both workflow analysis and workflow transformation. An RT is similar to a program structure tree and imposes a hierarchy of regions as an overlay structure onto the workflow model. It allows an incremental approach to the analysis and transformation of workflows, and thereby, significantly reduces the overhead because individual regions can be dealt with separately. The RT is built using a set of region-growing rules. The set of rules presented here is shown to be correct and complete in the sense that a workflow is region-reducible as defined through these rules if and only if it is semantically sound.

Analysis of workflows in terms of structural correctness is important for ensuring the quality of workflow models. Typically, this analysis is only one step in a larger development process, followed by further transformation steps that lead from high-level models to more refined models until the workflow can finally be deployed on the underlying workflow engine of the production system. For practical and scalable applications, analysis and transformations of workflows must both be integrated to allow incremental changes of larger workflows. In this paper, we introduce the concept of a region tree for workflow models that can be used as the central data structure for both workflow analysis and workflow transformation. A region tree is similar to a program structure tree and imposes a hierarchy of regions onto the workflow model. It allows an incremental approach to analysis and transformation of workflows and thereby significantly reduces the overhead because individual regions can be dealt with separately

Modeling embedded real time systems consisting of different components with UML-RT leads to a design model using various diagrams. Sequence diagrams describe possible interactions between system components and may be annotated with specific real time constraints. Statechart diagrams are used for describing each component's behavior. In order to be able to get a consistent model, a consistency concept for different diagram types is needed that takes into account real time constraints. A consistency concept for sequence diagrams and statechart diagrams is presented which focuses on the establishment of timing constraints. Our consistency concept distinguishes between syntactical, semantic and real time consistency and takes into account the influence of processor allocation and scheduling. Using the consistency concept, we describe a method for ensuring the consistency based on worst case execution time analysis of statecharts and schedulability analysis of tasks, thereby enabling a precise answer to the question of consistency.

Object-oriented modeling favors the modeling of object behavior from different viewpoints and the successive refinement of behavioral models in the development process. This gives rise to consistency problems of behavioral models. The absence of a formal semantics for UML models and the numerous possibilities of employing behavioral models within the development process lead to the rise of a number of different consistency notions. In this paper, we discuss the issue of consistency of behavioral models in the UML and present a general methodology how consistency problems can be dealt with. According to the methodology, those aspects of the models relevant to the consistency are mapped to a semantic domain in which precise consistency tests can be formulated. The choice of the semantic domain and the definition of consistency conditions can be used to construct different consistency notions. We show the applicability of our methodology by giving an example of a concrete consistency problem of concurrent object-oriented models.

For the generic specification of protocols, goals, or workflows, many approaches to agent-oriented modeling provide a concept of role. Roles abstract from the concrete agents involved in an interaction. They provide means for the evolution of agents and serve as components of agent design. Despite the widespread usage of roles in agent-oriented modeling, a systematic analysis of the different aspects and properties of this concept is still missing. In this paper, we perform such an analysis and identify requirements for a general role concept. We develop such a role concept for a modeling approach based on the UML and graph transformation systems and exemplify its use for the specification (and application) of protocols. Finally, we provide a run-time semantics for roles based on concepts from the theory of graph transformation.