Process-based composition of Web services is emerging as a promising technology for the effective automation of integrated and collaborative applications. As Web services are often autonomous and heterogeneous entities, coordinating their interactions to build complex processes is a difficult, error prone, and time-consuming task. In addition, since Web services usually operate in dynamic and highly evolving environments, there is a need for supporting flexible and correct execution of integrated processes. In this thesis, we propose a Petri net-based framework for formal composition and recovery policies in service-based business processes. We first propose an algebra for composing Web services. The formal semantics of this algebra is expressed in terms of Petri nets. The use of a formal model allows the effective verification and analysis of properties, both within a service, such as termination and absence of deadlock, and between services, such as behavioral equivalences. We also develop a top down approach for the correct (e.g., absence of deadlock and termination) composition of complex business processes. The approach defines a set of refinement operators that guarantee correctness of the resulting business process nets at design time. We then introduce Self-Adaptive Recovery Net (SARN), an extended Petri net model for specifying exceptional behavior in business processes. SARN adapts the structure of the underlying Petri net at run time to handle exceptions while keeping the Petri net design simple and easy. The proposed framework caters for the specification of high-level recovery policies that are incorporated either with a single task or a set of tasks, called a recovery region. Finally, we propose a pattern-based approach to dynamically restructure SARN. These patterns capture the ways past exceptions have been dealt with. The objective is to continuously restructure recovery regions within the SARN model to minimize the impact of exception handling. To illustrate the viability of the proposed composition and exception handling techniques, we have developed HiWorD (HIerarchical WORkflow Designer), a hierarchical Petri net-based business process modeling and simulation tool.

Web services composition is emerging as a promising technology for the effective automation of application-to-application collaborations. The application integration problems have been subject of much research in the past years. However, with growth in importance of business process automation and highly dynamic nature of the Internet, this research has taken on a new significance and importance. Adequate solutions to this problem will be very important to make enterprise systems more flexible, robust and usable in the future. In this dissertation, we present a novel approach for the declarative definition and scalable orchestration of composite Web services in large, autonomous, heterogeneous, and dynamic environments. We first propose a composition model for composing Web services in a personalized and adaptive manner. We model composite Web services based on statecharts. To cater for large amounts of dynamic Web services, we use the concept of service community that groups services together and is responsible for the runtime selection of services against user's preferences. We use the concept of process schema that specific users can adjust with their personal preferences. A set of exception handling policies can be specified to proactively react to runtime exceptions. We then propose a tuple space based service orchestration model for distributed, self-managed composite services execution. We introduce the concept of execution controller that is associated with a service and is responsible for monitoring and controlling service executions. The knowledge required by a controller is statically extracted from the specification of personalized composite services. We also present techniques for robust Web services provisioning. The techniques presented in this dissertation are implemented in Self-Serv, a prototype that provides a set of tools for Web service composition and execution. Finally, we conduct an extensive usability and performance study of the proposed techniques. The experimental results reveal that our system i) provides an efficient support for specifying, deploying, and accessing composite services; ii) is more scalable and outperforms the centralized approach when the exchanged messages become bigger; and iii) is more robust and adaptive in highly dynamic environments.

網際網路的高速且高度成長，使得今日的網路應用及服務日趨豐富化，網路化理財的觀念，也因此而得以實現。但網路理財牽涉到諸多系統的整合問題，使得目前各金融機構在網路所提供的網路理財服務，在各方面資訊提供及應用上都顯得有限且重複性過高，網路理財的真正效益並沒有真正的達到最大化。網路上各個功能系統的相互獨立，要提供一完整性的解決方案在系統整合上已經是一大瓶頸，再者網路服務的使用者在使用服務時皆受限於網路應用系統本身的功能及資源，使用者無法真正的具備網路服務在選取及使用上的自主性。 　　在本研究中將試圖以XML Web Service的技術架構，建置一整合性的應用服務平台，讓平台能快速的和網路上任一網路應用提供者整合，並能整合網際網路上服務提供者所提供的服務，讓系統和系統間、使用者和系統間，都是以鬆散耦合結構來進行互動。使用者在使用網路服務時也能擺脫過去受限於網站應用提供資及應用上的限制，讓使用者在使用網路服務時能根據自己的需求進行個人化的服務選用，讓使用者得到的是即時性、個人化、整合性的資訊。

<p>Byggnadsautomation har i dagsläget ett kalkylprogram gjort i Excel som är helt fristående från deras kvalitetsprogram. Dom vill i och med detta få ett två delat system som användaren både ska kunna köra med eller utan anknytning till Internet. Programmet har tillgång till en befintlig kund och komponentregister som man kommer åt via en Web Service. Om det inte finns någon Internet uppkoppling så kommer dessa register att sparas lokalt för att sedan synkroniseras när det finns tillgång till Internet. En kalkyl ska kunna sparas och öppnas antingen på servern eller lokalt som i detta fall är en SQLite databas. Själva applikationen kommer att utvecklas i .NET miljö i C#.</p>

Model integration that allows multiple models to work together for solving a sophisticated problem has been an important research issue in the management of decision models. The recent development of the service-oriented architecture (SOA) has provided an opportunity to apply this new technology to support model integration. This is particularly critical when more and more models are delivered as web services. A web-services-based approach to model management is useful in providing effective decision support. In the past, existing literature has adopted the approach that treated a model as a service. Model integration can be thought of as a composition of web services. In the composition process, proper components and their relationships must be properly identified. This requires accurate model definition and reasoning. In the research, we propose a semantic-based approach for developing such as system. The approach uses DAML-S to describe the capability of a service. Then the system can discover proper services for a particular requirement by using semantic matching on these DAML-S documents. When suitable web services are found, the system uses BPEL4WS to composite them together. The resulting composite web service can be applied to decision support. A prototype that demonstrates the feasibility of the proposed approach is implemented in Java.

Usage of smart phones has become more common nowadays. Timelog system is a user friendly and web based application which systemizes the business of a company with the focus on time tracking. Following the Timelog system from small screen of smart phones is not user-friendly because the Timelog application and its features have not been designed to be accessed from these devices. The solution is creating a smart phone client for the Timelog system which can connect to the database of the system. An appropriate approach is to design a Web Service as an intermediate layer to communicate between the client side and the database.The result is a smart phone client that can be used by users of Timelog system to manage their business when they use their mobiles instead of personal computers. The Web Service can also be used for other smart phone platforms. As a result it can be considered as a generic protocol for the mobile-user of Timelog system.

Service Oriented Computing(SOC) is becoming a major paradigm for developing next generation of software systems, and one of the major challenges of Service Oriented Computing is testing interactions and collaborations among the distributed and dynamically integrated web services. To support automated test of web service‟s collaborations, a formal specification is needed. This thesis proposes a specification of web services collaborations based on Web Services Choreography Description Language (WS-CDL). We identify the basic constructs that can be found in any web services collaboration, and we mapped them to the new WS-CDL based language (WS-CDL+). Finally, A scenario of web services collaboration is developed and specification in WS-CDL+ is provided. This work builds a foundation for automated web services testing in a service oriented computing environment.

Making a communication tool easier for people to operate can have profound and positive effects on its popularity and on the users themselves. This thesis is about making it easier for people to publish web-based documents that have sound, video and text. Readily available software and hardware are employed in an attempt to achieve the goal of providing a software service that enables users to compose audio-video documents with text.

Simulation software is being increasingly used in various domains for system analysis and/or behavior prediction. Traditionally, researchers and field experts need to have access to the computers that host the simulation software to do simulation experiments. With recent advances in cloud computing and Software as a Service (SaaS), a new paradigm is emerging where simulation software is used as services that are composed with others and dynamically influence each other for service-oriented simulation experiment on the Internet. The new service-oriented paradigm brings new research challenges in composing multiple simulation services in a meaningful and correct way for simulation experiments. To systematically support simulation software as a service (SimSaaS) and service-oriented simulation experiment, we propose a layered framework that includes five layers: an infrastructure layer, a simulation execution engine layer, a simulation service layer, a simulation experiment layer and finally a graphical user interface layer. Within this layered framework, we provide a specification for both simulation experiment and the involved individual simulation services. Such a formal specification is useful in order to support systematic compositions of simulation services as well as automatic deployment of composed services for carrying out simulation experiments. Built on this specification, we identify the issue of mismatch of time granularity and event granularity in composing simulation services at the pragmatic level, and develop four types of granularity handling agents to be associated with the couplings between services. The ultimate goal is to achieve standard and automated approaches for simulation service composition in the emerging service-oriented computing environment. Finally, to achieve more efficient service-oriented simulation, we develop a profile-based partitioning method that exploits a system’s dynamic behavior and uses it as a profile to guide the spatial partitioning for more efficient parallel simulation. We develop the work in this dissertation within the application context of wildfire spread simulation, and demonstrate the effectiveness of our work based on this application.

Simulation software is being increasingly used in various domains for system analysis and/or behavior prediction. Traditionally, researchers and field experts need to have access to the computers that host the simulation software to do simulation experiments. With recent advances in cloud computing and Software as a Service (SaaS), a new paradigm is emerging where simulation software is used as services that are composed with others and dynamically influence each other for service-oriented simulation experiment on the Internet. The new service-oriented paradigm brings new research challenges in composing multiple simulation services in a meaningful and correct way for simulation experiments. To systematically support simulation software as a service (SimSaaS) and service-oriented simulation experiment, we propose a layered framework that includes five layers: an infrastructure layer, a simulation execution engine layer, a simulation service layer, a simulation experiment layer and finally a graphical user interface layer. Within this layered framework, we provide a specification for both simulation experiment and the involved individual simulation services. Such a formal specification is useful in order to support systematic compositions of simulation services as well as automatic deployment of composed services for carrying out simulation experiments. Built on this specification, we identify the issue of mismatch of time granularity and event granularity in composing simulation services at the pragmatic level, and develop four types of granularity handling agents to be associated with the couplings between services. The ultimate goal is to achieve standard and automated approaches for simulation service composition in the emerging service-oriented computing environment. Finally, to achieve more efficient service-oriented simulation, we develop a profile-based partitioning method that exploits a system’s dynamic behavior and uses it as a profile to guide the spatial partitioning for more efficient parallel simulation. We develop the work in this dissertation within the application context of wildfire spread simulation, and demonstrate the effectiveness of our work based on this application.