Showing papers on "Process architecture published in 2018"

Modeling Self-Adaptive Software Systems by Fuzzy Rules and Petri Nets

Abstract: A self-adaptive software system is one that can autonomously modify its behavior at runtime in response to changes in the system and its environment. It is a challenge to model such a kind of systems since it is hard to predict runtime environmental changes at the design phase. In this paper, a formal model called intelligent Petri net (I-PN) is proposed to model a self-adaptive software system. I-PN is formed by incorporating fuzzy rules to a regular Petri net. The proposed net has the following advantages. 1) Since fuzzy rules can express the behavior of a system in an interpretable way and their variables can be reconfigured by the runtime data, the proposed model can model runtime environment and system behavior. 2) Since a fuzzy inference system with well-defined semantics can be used in a complementary way with other model languages for the analysis, thus the proposed model can be analyzed, even though it is described in two different languages: component behaviors in Petri nets while logic control in fuzzy rules. 3) The proposed model has self-adaption ability and can make adaptive decisions at runtime with the help of fuzzy inference reasoning. We adopt a manufacturing system to show the feasibility of the proposed model.

Prototyping of Concurrent Control Systems With Application of Petri Nets and Comparability Graphs

Abstract: This paper shows a novel prototyping technique for concurrent control systems described by interpreted Petri nets. The technique is based on the decomposition of an interpreted Petri net into concurrent sequential automata. In general, minimum decomposition requires runtime that is exponential in the number of Petri net places. We show that in many cases, including the real-life ones, the minimum decomposition problem can be solved in polynomial time. The proposed method allows implementing a concurrent control system using minimal number of sequential components, which requires polynomial time and can be applied to most of the considered cases. The presented concept is illustrated by a real-life industrial example of a beverage production and distribution machine implemented in a field programmable gate array.

Structural Decomposition and Decentralized Control of Petri Nets

Abstract: Control of a large-scale automated manufacturing system is an important and challenging issue. Its discrete event system model represented by Petri nets tends to become highly complicated in structure, especially when there exist uncontrollable or unobservable events. The existing approaches are nontrivial to design both efficient and maximally permissive supervisors to impose constraints on an overall system. In this paper, instead of considering the control problem from an overall system perspective, we intend to transform an overall control problem into the one designing multiple controllers in parallel, each of which is much simpler in structure. A Petri net structure is decomposed via integer linear programming or a polynomial decomposition method to obtain multiple state-machine subnets that constitute a decentralized system. A necessary and sufficient condition for preserving the equivalence in terms of states and behaviors between the overall system and its decentralized version is reported. Constraints representing control requirements are further converted and enforced in the respective subnets. Then, supervisors are generated via a generalized mutual exclusion constraint method. By considering the deviations between the subnet control and overall control, this paper formulates a communication mechanism to guarantee that the decentralized system runs in an appropriate manner. Finally, two examples are presented to demonstrate the proposed approach.

Modular Petri net modeling of healthcare systems

Abstract: This paper presents a modular approach for modeling healthcare systems using Petri nets. It is shown that a healthcare system can be constructed by different modules whose inputs and outputs are connected according to their geographical location. Each module can be modeled in two phases: (1) obtain the sequences of treatments and cares received by a patient in the case of a particular disease/condition, and (2) add the resources necessary to perform the previous sequences. The global model is obtained by fusion the inputs and outputs of the modules and by adding information on the patients. The constructed modules together with the resources are Petri nets belonging to a new subclass called healthcare Petri nets that is proved to have equivalent behavior with $$S^4{\textit{PR}}$$ nets, a well-known class of Resource Allocation Systems. This allows us to apply the structural results already existing in the literature for $$S^4{\textit{PR}}$$ to the context of healthcare systems. In order to illustrate the results, a case study of a public healthcare area in Zaragoza is considered as a use case.

Analyzing E-Commerce Business Process Nets via Incidence Matrix and Reduction

Abstract: E-commerce business process nets (EBPNs) are a novel formal model for describing and validating e-commerce systems including interactive parties such as shopper, merchant, and third-party payment platform. Data errors and nondeterminacy of the data states during the trading process can be depicted with the help of EBPNs. However, the problem about how to analyze EBPNs remains largely open. To analyze their data-liveness, data-boundedness, and reachability, this paper presents two analysis methods. For EBPNs, reachability analysis is proposed based on a 3-D incidence matrix method. Additionally, reduction methods are proposed for a special EBPN. Finally, the validity and reliability of the proposed methods are illustrated via the examples of e-commerce systems.

Scenario-based system design with colored Petri nets: an application to train control systems

Abstract: For the goal of model-based system software development, this paper exploits the formalism of colored Petri nets (CPNs) to design complex systems based on scenarios. The specification of UML sequence diagrams which are easily understood by customers, requirement engineers and software developers are adopted to represent scenarios as specification models. A scenario is a partial description of the system behavior, describing how users, system components and the environment interact. Thus scenarios need to be synthesized in order to obtain an overall system behavior. A large number of works (e.g., Whittle and Schumann in Proceedings of the 2000 international conference on software engineering, pp 314---323, 2000; Elkoutbi and Keller in Application and theory of Petri nets, 2000; Damas et al. in Proceedings of the 14th ACM SIGSOFT international symposium on foundations of software engineering, pp 197---207, 2000; Uchitel et al. in IEEE Trans Softw Eng 29(2):99---115, 2003) have investigated scenario synthesis providing approaches or algorithms. These synthesis approaches and algorithms result in either Petri net models (e.g., Elkoutbi and Keller 2000; Ameedeen and Bordbar in 12th international IEEE enterprise distributed object computing conference (EDOC), pp 213---221, 2008) that are mainly suitable for scenario validation or other forms of behavior models (e.g., labeled transition systems in Damas et al. 2000; Uchitel et al. 2003 and statecharts in Kruger et al. in Distributed and parallel embedded systems, pp 61---71, 1999; Whittle et al. 2000) that may be regarded as design models. Petri nets are well known for describing distributed and concurrent complex systems. Furthermore, numerous techniques, e.g., simulation, testing, state space-based techniques, structural methods and model checking, are currently available for analyzing Petri net models. Therefore, design models in the form of Petri nets, integrating all scenarios into a coherent whole and fitting for further detailed design, are promising. To this end, we present a top-down approach to establish hierarchical CPNs in accordance with specified scenarios (i.e., sequence diagrams). This approach makes use of explicitly labeling component states in the sequence diagrams to correlate scenarios. In addition, the techniques of state space analysis and ASK-CTL model checking are used to verify the correctness and consistency of the CPN model with respect to standard and system-specific properties. As the inspiration of the presented approach derives from the development of train control systems, we present an running example of designing the on-board subsystem of a satellite-based train control system to show the feasibility of our approach.

Discovering Petri Net Models of Discrete-Event Processes by Computing T-Invariants

Abstract: This paper addresses the problem of discovering a Petri Net (PN) from a long event sequence representing the behavior of discrete-event processes A method for building a 1-bounded PN able to execute the events sequence $S$ is presented; it is based on determining causality and concurrence relations between events and computing the t-invariants This novel method determines the structure and the initial marking of an ordinary PN, which reproduces the behavior in $S$ The algorithms derived from the method are efficient and have been implemented and tested on numerous examples of diverse complexity Note to Practitioners —Model discovery is useful to perform reverse engineering of ill-known systems The algorithms proposed in this paper build 1-bounded PN models, which are enough powerful to describe many discrete-event processes from industry The efficiency of the method allows processing very large sequences Thus, an automated modeling tool can be developed for dealing with data issued from real systems

Static analysis and process model transformation for an advanced business process to Petri net mapping

Abstract: Summary Verification of business processes typically relies on Petri net–based process models. While they allow for natural modeling and analysis of aspects such as parallelism and message exchange, such a process model is seldom complete and precise. This is mainly because the available techniques for deriving a Petri net model from the original model neglect process data in favor of feasible verification. In this paper, we present an approach for deriving more precise process models by leveraging a process-to-Petri-net compiler, which takes as input a business process and generates as output a Petri net model for the process. This can be subsequently used for verification. However, in contrast to a conventional compiler, our compiler's objective is not to create the most efficient code but rather to produce a most precise but still effectively verifiable Petri net–based process model.

Process architecture development using Riva and ARIS: comparative study

Abstract: Business process modeling has been given great attention due to its crucial role in developing computer-based systems that support (and automate) organizational processes. In information systems, building the right process architecture is vital, since a poor division of organizational processes can lead to complex designs or incoherent structure. Moreover, process architecture acts as a “big picture” of what the organization does, and represents dynamic relationships between the existing processes, which, in turn, helps understand how the organization works (Ould, 2005). The paper aims to discuss these issues.,This paper discusses the derivation of a process architecture diagram (PAD) using the Riva method in detail, in contrast to the PAD developed using Architecture of Integrated Information Systems (ARIS). The information system selected as an example for this comparative study is in the context of academic libraries, embedding various yet generic library processes.,Organizational process architecture provides a basis for business management, based on specific framework supported by integrated tools and methods (Kozina, 2006). ARIS and Riva process architecture methods can be used to visualize and document organizational processes. Understanding the merits and weaknesses of each method is essential to identify possible areas of application.,The processes selected were generic in most academic libraries not taking into consideration special personalized processes. These can be added though.,Both techniques are feasible and can be used to view and analyze library processes, allowing bridging the gap between theory and practice.,A number of process architecture methods are available, however, few studies focused on assessing these methods, and comparing some of them to find out how easy they are to be used in particular contexts, and whether they can be standardized.

Derivation of a Semantic Cancer Care Information Architecture from Riva-based Business Process Architecture using the BPAOntoEIA Framework

Abstract: Contemporary Enterprise Information Architecture (EIA) design methods lack the knowledge of business process in an enterprise. The object-based business process architecture (BPA) design methods generate useful information of business entities and process that can assist in deriving a business process-aware EIA in a semi-automatic manner. This paper reports on the impact of applying the BPAOntoEIA framework to a Cancer Care & Registration actual case study in order to derive a semantic EIA from its associated Riva-based BPA semantic model. The benefit of this framework manifests itself in the knowledge of business processes, their orchestration and models of the cancer care organisation while inter-connecting the business processes with information categories, and thus enhancing the business-IT alignment of the given cancer care & Registration process architecture. An automation of 80% of the semantic EIA derivation is reported and EIA quality metrics were developed that have informed the evaluation of the automated derivation of a corresponding Cancer Care and Registration EIA.

Performance Evaluation and Control of Manufacturing Systems A Continuous Petri Nets View

Abstract: Manufacturing systems can be naturally viewed as discrete event systems (DESs). This chapter discusses the basic concepts, properties and theoretical results of autonomous and timed Continuous Petri Nets (TCPN), as well as steady state and dynamic control with classical discrete models. It presents some important concepts and properties about Continuous Petri Nets (CPN), both for the autonomous model and the timed model. Without time interpretation, the autonomous model can be used to analyse some behavioural properties, like boundedness, deadlock-freeness (DF) and, liveness. CPNs are relaxations of discrete Petri Nets (PN), but at the same time, they are also continuous-state technically, hybrid systems. Then, it is reasonable to consider the following two different approaches related to the control: the extension of control techniques used in discrete PN, such as the supervisory control theory, and the extension of control techniques developed for classical continuous-state systems.

“Simply Modeling”: BPM for Everybody-Recommendations from the Viral Adoption of BPM at 1&1

Abstract: (a) Situation faced: 1&1 is a German Internet service provider that embraced business process management (BPM) in 2010 as a way to optimize its processes. The company expected BPM to increase corporate performance by realizing such customer-centric goals as high quality standards, reduced set-up times, shortened time-to-market cycles, and increased adaptability to changing customer requirements. 1&1 decided to use the Business Process Model and Notation (BPMN) for its business process models, but the specification offers no pragmatic advice on how to introduce and adapt the modeling method in a company. 1&1 started with a conceptual process architecture—a lightweight process modeling infrastructure—and invested in a BPM initiative using a bottom-up approach. The resulting viral spread of BPM led to a “success disaster” with a high adoption rate and a high number of models but low model quality. (b) Action taken: 1&1 turned around the proliferating trend of low quality and barely usable process models by means of carefully targeted decisions. An initial analysis showed that the key factors in the disastrous situation were insufficient training and the lack of modeling conventions. While no changes were made to the process architecture, the company increased the integration of system architecture components, resulting in improved knowledge management as increasing amounts of information became retrievable through the enterprise information portal. Quality assurance was mandated through a few selected modeling conventions to guide and constrain but not restrict the modelers. Finally, the BPM initiative grew larger with more volunteer trainers and more differentiated courses that helped to ensure an appropriate level of process modeling competence for each employee’s tasks. (c) Results Achieved: Because of its lightweight implementation, BPM at 1&1 can enable continuous process adjustments triggered by any employee at any time and on every level, so it can achieve short time-to-market for core business products and services, as well as rapid changes in business processes. Business knowledge and expertise is extracted from all of the company’s corporate levels and is merged and presented in the process models. The company currently uses as its production environment the Signavio Process Editor, which relies on a repository of more than 12,000 process models and more than 1800 active process modelers. (d) Lessons learned: The BPMN specification provides no guidance on how to introduce and use BPMN in the individual corporate context. While it is often useful to follow a reference approach for the adaptation and use of a modeling method and the associated IT infrastructure, there is none available for BPMN. Based on the 1&1 case, we present recommendations that can be considered best practices for setting up and steering a large-scale BPM initiative based on process modeling that emphasize process modeling technology, user training, modeling regulations, employee management, and time management.

A Tool for Traceable Evolution of Process Architectures

Abstract: Evolving process architectures involves incremental enhancements to process components and inter-connections with time. In order to keep track of evolution of both parts and the whole, traceability through this evolution over a time continuum is essential. The paper presents a tool to manage and reason through evolution of process architectures. The tool uses graph based analysis techniques to facilitate reasoning through continuous modifications made to evolving process architecture. It implements a technique called Process Edification, achieving evolution and its traceability around both parts and the whole. The ideas behind the tool are illustrated and the tool is demonstrated with the help of a case of an evolving BPMN process.

A scheme for the simulation of networked agent systems modeled by timed hybrid Petri nets

Abstract: A novel scheme for simulating networked agent systems is presented. In this approach, the system is composed of identical communicating agents, which have multi-role capabilities in such a manner t...

Approaching the potential of cyber-physical systems to tourism projects

Abstract: We are witnessing the need for a quick and intelligent reaction from organizations to the level and speed of change in business processes. This is often associated with the emerging of new information systems and technologies, bursting problems like the persistence of wrong information, systems not fully used and slow response. This requires two main actions: synchronizing people’s visions and strategies within the organization and selecting the information which is relevant for the strategic goals. The main challenge of the proposed approach is to choose the information systems’ portfolio management aligned with the enterprise architecture. This integration leads to modelling the process architecture of the company, which in turn serves as a reference for knowledge-base management to cope with business prospects. This kind of flexible framework can contribute to managing the potential adherence to new systems such as the mobile, cloud, big-data or IoT-based services that tend to proliferate especially in such areas as tourism and health.

Modeling and Analyzing Process Architecture for Context-Driven Adaptation: Designing Cognitively-Enhanced Business Processes for Enterprises

Abstract: Organizations are increasingly looking to adopt and incorporate cognitive capabilities into key business processes to aid human decision-making activities. The availability of context data helps with improved decision-making involving both human users and cognitive systems, while ensuring continuing satisfaction of enterprise objectives. Therefore, the ongoing monitoring, selection and management of context data for redesigning sections of the overall business process structure, particularly where the cognitive systems are integrated in business processes, is of great inter-est. This paper proposes a systematic model-based approach to visualize the detection of context changes in a business process, determine an appropriate response to this context change, and identify the corresponding reconfiguration of processes in another part of the enterprise. This paper not only handles context, but also looks at the processes that need to respond to changes in that context. Together these processes constitute a business process architecture. This enables business process reconfiguration to better integrate cognitive systems in process activities requiring decision-making. The use of such modeling techniques facilitates the investigation of multiple process configurations while considering satisfaction of functional and non-functional objectives and ongoing contextual changes.

Process Design II: Designing for Breakthroughs

Abstract: This chapter is an in-depth explanation of the nearly universal grammar—or process architecture—that underlies facilitating creative breakthroughs. The advantage of using a process architecture for designing co-creative programs is that it provides a framework to place the techniques we know into an optimal arrangement. By optimal, we mean a form and flow of activities that create a good container, the space between, and then harness the insights that come forth. There are several experience design principles that help accomplish these goals. We call these “intangibles,” mainly because they cannot be directly measured with any scientific instruments. Yet people feel these, sometimes consciously and sometimes not.