Model-driven design, simulation and implementation of service compositions in COSMO

The success of software development projects to a large extent depends on the quality of the models that are produced in the development process, which in turn depends on the conceptual and practical support that is available for modelling, design and analysis. This paper focuses on model-driven support for service-oriented software development. In particular, it addresses how services and compositions of services can be designed, simulated and implemented. The support presented is part of a larger framework, called COSMO (COnceptual Service MOdelling). Whereas in previous work we reported on the conceptual support provided by COSMO, in this paper we proceed with a discussion of the practical support that has been developed. We show how reference models (model types) and guidelines (design steps) can be iteratively applied to design service compositions at a platform independent level and discuss what tool support is available for the design and analysis during this phase. Next, we present some techniques to transform a platform independent service composition model to an implementation in terms of BPEL and WSDL. We use the mediation scenario of the SWS challenge (concerning the establishment of a purchase order between two companies) to illustrate our application of the COSMO framework

An approach to enacting business process models in support of the life cycle of integrated manufacturing systems

The complexity of enterprise engineering processes requires the application of reference architectures as means of guiding the achievement of an adequate level of business integration. This research aims to address important aspects of this requirement by associating the formalism of reference architectures to various life cycle phases of integrating manufacturing systems (IMS) and enabling their use in addressing contemporary system engineering issues. In pursuit of this aim, the following research activities were carried out: (1) to devise a framework which supports key phases of the IMS life cycle and (2) to populate part of this framework with an initial combination of architectures which can be encapsulated into a computer-aided systems engineering environment. This has led to the creation of a workbench capable of providing support for modelling, analysis, simulation, rapid-prototyping, configuration and run-time operation of an IMS, based on a consistent set of models associated with the engineering processes involved. The research effort concentrated on selecting and investigating the use of appropriate formalisms which underpin a selection of architectures and tools (i. e. CIM-OSA, Petrinets, object-oriented methods and CIM-BIOSYS), this by designing, implementing, applying and testing the workbench. The main contribution of this research is to demonstrate that it is possible to retain an adequate level of formalism, via computational structures and models, which extend through the IMS life cycle from a conceptual description of the system through to actions that the system performs when operating. The underlying methodology which supported this contribution is based on enacting models of system behaviour which encode important coordination aspects of manufacturing systems. The strategy for demonstrating the incorporation of formalism to the IMS life cycle was to enable the aggregation into a workbench of knowledge of 'what' the system is expected to achieve (i. e. 'problems' to be addressed) and 'how' the system can achieve it (i. e possible 'solutions'). Within the workbench, such a knowledge is represented through an amalgamation of business process modelling and object-oriented modelling approaches which, when adequately manipulated, can lead to business integration

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

The Impact of Petri Nets on System-of-Systems Engineering

The successful engineering of a large-scale system-of-systems project towards deterministic behaviour depends on integrating autonomous components using international communications standards in accordance with dynamic requirements. To-date, their engineering has been unsuccessful: no combination of top-down and bottom-up engineering perspectives is adopted, and information exchange protocol and interfaces between components are not being precisely specified. Various approaches such as modelling, and architecture frameworks make positive contributions to system-of-systems specification but their successful implementation is still a problem. One of the most popular modelling notations available for specifying systems, UML, is intuitive and graphical but also ambiguous and imprecise. Supplying a range of diagrams to represent a system under development, UML lacks simulation and exhaustive verification capability. This shortfall in UML has received little attention in the context of system-of-systems and there are two major research issues: 1. Where the dynamic, behavioural diagrams of UML can and cannot be used to model and analyse system-of-systems 2. Determining how Petri nets can be used to improve the specification and analysis of the dynamic model of a system-of-systems specified using UML This thesis presents the strengths and weaknesses of Petri nets in relation to the specification of system-of-systems and shows how Petri net models can be used instead of conventional UML Activity Diagrams. The model of the system-of-systems can then be analysed and verified using Petri net theory. The Petri net formalism of behaviour is demonstrated using two case studies from the military domain. The first case study uses Petri nets to specify and analyse a close air support mission. This case study concludes by indicating the strengths, weaknesses, and shortfalls of the proposed formalism in system-of-systems specification. The second case study considers specification of a military exchange network parameters problem and the results are compared with the strengths and weaknesses identified in the first case study. Finally, the results of the research are formulated in the form of a Petri net enhancement to UML (mapping existing activity diagram elements to Petri net elements) to meet the needs of system-of-systems specification, verification and validation

A Framework for Executable Systems Modeling

Systems Modeling Language (SysML), like its parent language, the Unified Modeling Language (UML), consists of a number of independently derived model languages (i.e. state charts, activity models etc.) which have been co-opted into a single modeling framework. This, together with the lack of an overarching meta-model that supports uniform semantics across the various diagram types, has resulted in a large unwieldy and informal language schema. Additionally, SysML does not offer a built in framework for managing time and the scheduling of time based events in a simulation. In response to these challenges, a number of auxiliary standards have been offered by the Object Management Group (OMG); most pertinent here are the foundational UML subset (fUML), Action language for fUML (Alf), and the UML profile for Modeling and Analysis of Real Time and Embedded Systems (MARTE). However, there remains a lack of a similar treatment of SysML tailored towards precise and formal modeling in the systems engineering domain. This work addresses this gap by offering refined semantics for SysML akin to fUML and MARTE standards, aimed at primarily supporting the development of time based simulation models typically applied for model verification and validation in systems engineering. The result of this work offers an Executable Systems Modeling Language (ESysML) and a prototype modeling tool that serves as an implementation test bed for the ESysML language. Additionally a model development process is offered to guide user appropriation of the provided framework for model building

Search-based system architecture development using a holistic modeling approach

This dissertation presents an innovative approach to system architecting where search algorithms are used to explore design trade space for good architecture alternatives. Such an approach is achieved by integrating certain model construction, alternative generation, simulation, and assessment processes into a coherent and automated framework. This framework is facilitated by a holistic modeling approach that combines the capabilities of Object Process Methodology (OPM), Colored Petri Net (CPN), and feature model. The resultant holistic model can not only capture the structural, behavioral, and dynamic aspects of a system, allowing simulation and strong analysis methods to be applied, it can also specify the architectural design space. Both object-oriented analysis and design (OOA/D) and domain engineering were exploited to capture design variables and their domains and define architecture generation operations. A fully realized framework (with genetic algorithms as the search algorithm) was developed. Both the proposed framework and its suggested implementation, including the proposed holistic modeling approach and architecture alternative generation operations, are generic. They are targeted at systems that can be specified using object-oriented or process-oriented paradigm. The broad applicability of the proposed approach is demonstrated on two examples. One is the configuration of reconfigurable manufacturing systems (RMSs) under multi-objective optimization and the other is the architecture design of a manned lunar landing system for the Apollo program. The test results show that the proposed approach can cover a huge number of architecture alternatives and support the assessment of several performance measures. A set of quality results was obtained after running the optimization algorithm following the proposed framework --Abstract, page iii