A recursive paradigm for aligning observed behavior of large structured process models

The alignment of observed and modeled behavior is a crucial problem in process mining, since it opens the door for conformance checking and enhancement of process models. The state of the art techniques for the computation of alignments rely on a full exploration of the combination of the model state space and the observed behavior (an event log), which hampers their applicability for large instances. This paper presents a fresh view to the alignment problem: the computation of alignments is casted as the resolution of Integer Linear Programming models, where the user can decide the granularity of the alignment steps. Moreover, a novel recursive strategy is used to split the problem into small pieces, exponentially reducing the complexity of the ILP models to be solved. The contributions of this paper represent a promising alternative to fight the inherent complexity of computing alignments for large instances.Peer ReviewedPostprint (author's final draft

The DONS rail scheduling system

This paper describes a system for automated rail scheduling currently being developed at Dutch Rail (NS). This system will be used initially to base infrastructure decisions upon. Rail infrastructure poses constraints upon the rail schedules that can be made within it, because of the large extent in which trains share it. Good infrastructure is the one that allows good schedules. The Petri net based ExSpect editor is used to model infrastructure variants and to help converting them into schedule constraints. With OR techniques, schedules are then made generated. ExSpect is then used to simulate the execution of these schedules within their infrastructure

Development of a conceptual model of adaptive access rights management with using the apparatus of Petri nets

The paper describes the conceptual model of adaptive control of cyber protection of the informatization object (IO). Petri's Networks were used as a mathematical device to solve the problem of adaptive control of user access rights. The simulation model is proposed and the simulation in PIPE v4.3.0 package is performed. The possibility of automating the procedures for adjusting the user profile to minimize or neutralize cyber threats in the objects of informatization is shown. The model of distribution of user tasks in computer networks of IO is proposed. The model, unlike the existing, is based on the mathematical apparatus of Petri's Networks and contains variables that allow reducing the power of the state space. Access control method (ACM) is added. The addenda touched upon aspects of reconciliation of access rights that are requested by the task and requirements of the security policy and the degree of consistency of tasks and access to the IO nodes. Adjustment of rules and security metrics for new tasks or redistributable tasks is described in the notation of Petri nets

Model-based dependability analysis : state-of-the-art, challenges and future outlook

Abstract: Over the past two decades, the study of model-based dependability analysis has gathered significant research interest. Different approaches have been developed to automate and address various limitations of classical dependability techniques to contend with the increasing complexity and challenges of modern safety-critical system. Two leading paradigms have emerged, one which constructs predictive system failure models from component failure models compositionally using the topology of the system. The other utilizes design models - typically state automata - to explore system behaviour through fault injection. This paper reviews a number of prominent techniques under these two paradigms, and provides an insight into their working mechanism, applicability, strengths and challenges, as well as recent developments within these fields. We also discuss the emerging trends on integrated approaches and advanced analysis capabilities. Lastly, we outline the future outlook for model-based dependability analysis

A tool-supported approach to inter-tabular verification.

The use of decision tables to verify KBS has been advocated several times in the V&V literature. However, one of the main drawbacks of those system is that they fail to detect anomalies which occur over rule chains. In a decision table based context this means that anomalies which occur due to interactions between tables are neglected. These anomalies are called inter-tabular anomalies. In this paper we investigate an approach that deals with inter-tabular anomalies. One of the prerequisites for the approach was that it could be used by the knowledge engineer during the development of the KBS. This requires that the anomaly check can be performed on-line. As a result, the approach partly uses heuristics where exhaustive checks would be too inefficient. All detection facilities that will be described, have been implemented in a table-based development tool called PROLOGA. The use of this tool will be briefly illustrated. In addition, some experiences in verifying large knowledge bases are discussed.