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In this thesis a comprehensive verification framework is proposed to contend with some important issues in composability verification and a verification process is suggested to verify composability of different kinds of systems models, such as reactive, real-time and probabilistic systems. With an assumption that all these systems are concurrent in nature in which different composed components interact with each other simultaneously, the requirements for the extensive techniques for the structural and behavioral analysis becomes increasingly challenging. The proposed verification framework provides methods, techniques and tool support for verifying composability at its different levels. These levels are defined as foundations of consistent model composability. Each level is discussed in detail and an approach is presented to verify composability at that level. In particular we focus on the Dynamic-Semantic Composability level due to its significance in the overall composability correctness and also due to the level of difficulty it poses in the process. In order to verify composability at this level we investigate the application of three different approaches namely (i) Petri Nets based Algebraic Analysis (ii) Colored Petri Nets (CPN) based State-space Analysis and (iii) Communicating Sequential Processes based Model Checking. All three approaches attack the problem of verifying dynamic-semantic composability in different ways however they all share the same aim i.e., to confirm the correctness of a composed model with respect to its requirement specifications.

The discipline of component based modeling and simulation offers promising gains including reduction in development cost, time, and system complexity. It also promotes (re)use of modular components to build complex simulations. Many important issues in this area have been addressed, but composability verification is still considered a daunting challenge. In our observation most of the component based modeling frameworks possess weak built-in support for the composability verification, which is required to guarantee the correctness of the structural, behavioral and temporal aspects of the composition. In this paper we stage a practical approach to alleviate some of the challenges in composability verification and propose a process to verify composability of real-time system models. We emphasize on dynamic semantic level and present our approach using Colored Petri Nets and State Space analysis. We also present a Field Artillery model as an example of real-time system and explain how our approach verifies model composability., QC 20131128

The discipline of component-based modeling and simulation offers promising gains including reduction in development cost, time, and system complexity. This paradigm is very profitable as it promotes the use and reuse of modular components and is auspicious for effective development of complex simulations. It however is confronted by a series of research challenges when it comes to actually practice this methodology. One of such important issue is Composability verification. In modeling and simulation (M&S), composability is the capability to select and assemble components in various combinations to satisfy specific user requirements. Therefore to ensure the correctness of a composed model, it is verified with respect to its requirements specifications.There are different approaches and existing component modeling frameworks that support composability however in our observation most of the component modeling frameworks possess none or weak built-in support for the composability verification. One such framework is Base Object Model (BOM) which fundamentally poses a satisfactory potential for effective model composability and reuse. However it falls short of required semantics, necessary modeling characteristics and built-in evaluation techniques, which are essential for modeling complex system behavior and reasoning about the validity of the composability at different levels.In this thesis a comprehensive verification framework is proposed to contend with some important issues in composability verification and a verification process is suggested to verify composability of different kinds of systems models, such as reactive, real-time and probabilistic systems. With an assumption that all these systems are concurrent in nature in which different composed components interact with each other simultaneously, the requirements for the extensive techniques for the structural and behavioral analysis becomes increasingly challenging. The proposed verification framework pro, Overseas Scholarship for PHD in selected Studies Phase II Batch IHigher Education Commision of Pakistan.QC 20130224

The discipline of component-based modeling and simulation offers promising gains including reduction in development cost, time, and system complexity. This paradigm is very profitable as it promotes the use and reuse of modular components and is auspicious for effective development of complex simulations. It however is confronted by a series of research challenges when it comes to actually practice this methodology. One of such important issue is Composability verification. In modeling and simulation (M&S), composability is the capability to select and assemble components in various combinations to satisfy specific user requirements. Therefore to ensure the correctness of a composed model, it is verified with respect to its requirements specifications.There are different approaches and existing component modeling frameworks that support composability however in our observation most of the component modeling frameworks possess none or weak built-in support for the composability verification. One such framework is Base Object Model (BOM) which fundamentally poses a satisfactory potential for effective model composability and reuse. However it falls short of required semantics, necessary modeling characteristics and built-in evaluation techniques, which are essential for modeling complex system behavior and reasoning about the validity of the composability at different levels.In this thesis a comprehensive verification framework is proposed to contend with some important issues in composability verification and a verification process is suggested to verify composability of different kinds of systems models, such as reactive, real-time and probabilistic systems. With an assumption that all these systems are concurrent in nature in which different composed components interact with each other simultaneously, the requirements for the extensive techniques for the structural and behavioral analysis becomes increasingly challenging. The proposed verification framework pro, Overseas Scholarship for PHD in selected Studies Phase II Batch IHigher Education Commission of Pakistan.QC 20130224

The discipline of component-based modeling and simulation offers promising gains including reduction in development cost, time, and system complexity. This paradigm is very profitable as it promotes the use and reuse of modular components and is auspicious for effective development of complex simulations. It however is confronted by a series of research challenges when it comes to actually practice this methodology. One of such important issue is Composability verification. In modeling and simulation (M&S), composability is the capability to select and assemble components in various combinations to satisfy specific user requirements. Therefore to ensure the correctness of a composed model, it is verified with respect to its requirements specifications.There are different approaches and existing component modeling frameworks that support composability however in our observation most of the component modeling frameworks possess none or weak built-in support for the composability verification. One such framework is Base Object Model (BOM) which fundamentally poses a satisfactory potential for effective model composability and reuse. However it falls short of required semantics, necessary modeling characteristics and built-in evaluation techniques, which are essential for modeling complex system behavior and reasoning about the validity of the composability at different levels.In this thesis a comprehensive verification framework is proposed to contend with some important issues in composability verification and a verification process is suggested to verify composability of different kinds of systems models, such as reactive, real-time and probabilistic systems. With an assumption that all these systems are concurrent in nature in which different composed components interact with each other simultaneously, the requirements for the extensive techniques for the structural and behavioral analysis becomes increasingly challenging. The proposed verification framework pro, Overseas Scholarship for PHD in selected Studies Phase II Batch IHigher Education Commision of Pakistan.QC 20130224

The discipline of component-based modeling and simulation offers promising gains including reduction in development cost, time, and system complexity. This paradigm is very profitable as it promotes the use and reuse of modular components and is auspicious for effective development of complex simulations. It however is confronted by a series of research challenges when it comes to actually practice this methodology. One of such important issue is Composability verification. In modeling and simulation (M&S), composability is the capability to select and assemble components in various combinations to satisfy specific user requirements. Therefore to ensure the correctness of a composed model, it is verified with respect to its requirements specifications.There are different approaches and existing component modeling frameworks that support composability however in our observation most of the component modeling frameworks possess none or weak built-in support for the composability verification. One such framework is Base Object Model (BOM) which fundamentally poses a satisfactory potential for effective model composability and reuse. However it falls short of required semantics, necessary modeling characteristics and built-in evaluation techniques, which are essential for modeling complex system behavior and reasoning about the validity of the composability at different levels.In this thesis a comprehensive verification framework is proposed to contend with some important issues in composability verification and a verification process is suggested to verify composability of different kinds of systems models, such as reactive, real-time and probabilistic systems. With an assumption that all these systems are concurrent in nature in which different composed components interact with each other simultaneously, the requirements for the extensive techniques for the structural and behavioral analysis becomes increasingly challenging. The proposed verification framework pro, Overseas Scholarship for PHD in selected Studies Phase II Batch IHigher Education Commision of Pakistan.QC 20130224

The discipline of component-based modeling and simulation offers promising gains including reduction in development cost, time, and system complexity. This paradigm is very profitable as it promotes the use and reuse of modular components and is auspicious for effective development of complex simulations. It however is confronted by a series of research challenges when it comes to actually practice this methodology. One of such important issue is Composability verification. In modeling and simulation (M&S), composability is the capability to select and assemble components in various combinations to satisfy specific user requirements. Therefore to ensure the correctness of a composed model, it is verified with respect to its requirements specifications.There are different approaches and existing component modeling frameworks that support composability however in our observation most of the component modeling frameworks possess none or weak built-in support for the composability verification. One such framework is Base Object Model (BOM) which fundamentally poses a satisfactory potential for effective model composability and reuse. However it falls short of required semantics, necessary modeling characteristics and built-in evaluation techniques, which are essential for modeling complex system behavior and reasoning about the validity of the composability at different levels.In this thesis a comprehensive verification framework is proposed to contend with some important issues in composability verification and a verification process is suggested to verify composability of different kinds of systems models, such as reactive, real-time and probabilistic systems. With an assumption that all these systems are concurrent in nature in which different composed components interact with each other simultaneously, the requirements for the extensive techniques for the structural and behavioral analysis becomes increasingly challenging. The proposed verification framework pro, Overseas Scholarship for PHD in selected Studies Phase II Batch IHigher Education Commision of Pakistan.QC 20130224

Model reuse is a promising and appealing convention for effective development of simulation systems as it offers reduction in development cost and time. Various methodological advances in this area have given rise to the development of different component reusability frameworks such as BOM (Base Object Model). But lack of component matching and weak support for compos ability verification and validation, in these frameworks, makes it difficult to achieve effective and meaningful reuse. In this paper we focus on Compos ability verification and propose a process to verify BOM based composed model at dynamic semantic level. We suggest an extension to the BOM components, to capture behavior at a greater detail. Then we transform the extended BOM into our proposed Colored Petri Nets (CPN) based component model so that the components can be composed and executed at an abstract level. Subsequently we advocate to use CPN tools and analysis techniques to verify that the model satisfy given requirements. We classify the properties of a system among different groups and express the model's requirements by selecting some of the properties from these groups to form requirement specification. Also we present an example of a Field Artillery model, in which we select a set of properties as requirement specification, and explain how CPN state-space analysis technique is used to verify the required properties. Our experience confirms that CPN tools provide strong support for verification of composed models., QC 20121221

Model reuse is a promising and appealing convention for effective development of simulation systems. However it poses daunting challenges to various issues in research such as Reusability and Composability in model integration. Various methodological advances in this area have given rise to the development of different component reusability frameworks such as BOM (Base Object Model). However, lack of component matching and support for composability verification and validation makes it difficult to achieve effective and meaningful reuse. For this reason there is a need for adequate methods to verify and validate composability of a BOM based composed model. A verified composed model ensures the satisfaction of desired system properties. Fairness, as defined in section II, is an important system property which ensures that no component in a composition is delayed indefinitely. Fairness in a composed model guarantees the participation of all components in order to achieve the desired objectives. In this paper we focus on verification and propose to transform a composed BOM into a Petri Nets model and use different analysis techniques to perform its verification. We propose an algorithm to verify fairness property and provide a case study of a manufacturing system to explain our approach., QC 20111130

A verified composition of predefined reusable simulation components such as BOM (Base Object Model) plays a significant role in saving time and cost in the development of various simulations. BOM represents a reusable component framework and posses the ability to rapidly compose simulations but lacks semantic and behavioral expressiveness required to match components for a suitable composition. Moreover external techniques are required to evaluate behavioral verification of BOM based components. In this paper we discuss behavioral verification and propose an approach to verify the dynamic behavior of a set of composed BOM components against given specifications. We further define a Model Tester that provides means to verify behavior of a composed model during its execution. We motivate our verification approach by suggesting solutions for some of the categories of system properties. We also provide a case study to clarify our approach., QC 20120117

Reusability is a widely used concept which has recently receivedrenewed attention to meet the challenge of reducing cost and timeof simulation development. An approach to achieve effective reusabilityis through composition of predefined components which is promising buta daunting challenge in the research community. Base Object Model(BOM) is a component-based standard designed to support reusabilityand composability in distributed simulation community. BOM providesgood model representation for component reuse however this frameworklacks capability to express semantic and behavioral matching at the conceptuallevel. Furthermore there is a need for a technique to test thecorrectness of BOM-compositions in terms of structure and behavior. Inthis paper we discuss verification of BOM based model and test its suitabilityfor the intended purpose and objectives. We suggest a techniquethrough which the composed model can automatically be transformedinto a single Petri Net (PN) model and thus can further be verified usingdifferent existing PN analysis tools. We further motivate our approachby suggesting a deadlock detection technique as an example, and providea case study to clarify our approach., QC 20120124

Base Object Model (BOM) is a component-based standard designed to support reusability and Composability. Reusability helps in reducing time and cost of the development of a simulation process. Composing predefined components such as BOMs is a well known approach to achieve reusability. However, there is a need for a matching mechanism to identify whether a set of components are composable or not. Although BOM provides good model representation, it lacks capability to express semantic and behavioral matching. In this paper we propose an approach for matching behavior of BOM components by matching their statemachines. Our proposed process includcs a static and a dynamic matching phase. In the static matching phase, we apply a set of rules to validate the structure of statemachines. In the dynamic matching phase, we execute the statemachines together at an abstract level on our proposed execution framework. We have developed this, framework using the Slate Chart Extensible Markup Language (SCXML), which is a W3C compliant standard. If the execution terminates successfully (i.e. reaches specified final stales) we conclude that there is a positive match and the behavior of these BOMs is composable. We describe the matching process and the implementation of our runtime environment in detail and present a case study as proof of concept., QC 20110303

As Modelling and Simulation gains more popularity, the demand on reducing time and resource costs associated with development and validation of simulation models has also increased. Composing simulation models of reusable and validated simulation components is one approach for addressing the above demand. This approach requires a composition process that is able to support a modeller with discovery and identification of components as well as giving feedback on feasibility of a composition. Software agents are programs that can with some degree of autonomy perform tasks on behalf of a user or another program. In a Multi Agent System (MAS) autonomous agents interact and collaborate with each other in order to solve complex problems that are beyond the individual capabilities or knowledge of each agent, thus providing modularity and scalability. The objective of this work has been to develop a Multi Agent System for discovery and composition of BOM (Base Object Model) based simulation models, which provides the flexibility and adaptability to test and assess, amongst others different discovery and composition methods and techniques. The MAS that we developed is based on the JACK (TM) Intelligent Agents and executes a rule-based process for discovery and composition of BOMB. Our preliminary results indicate its feasibility, portability, adaptability and flexibility., QC 20100830