University of Macau / Faculty of Science and Technology / Department of Computer and Information Science

published_or_final_version / Business Administration / Master / Master of Business Administration

No description available.

Univ., Diss.--Hannover, 2002.

NR 20140805

Being faster is good. Being predictable is better. A faithful model of a system, loaded to reflect the system's current state, can then be used to look into the future and predict performance. Building faithful models of processes with high degrees of uncertainty can be very challenging, especially where this uncertainty exists in terms of processing times, queuing behavior and re-work rates. Within the context of an electronic, multi-tiered workflow management system (WFMS) the author builds such a model to endogenously quote due dates. A WFMS that manages business objects can be recast as a flexible flow shop in which the stations that a job (representing the business object) passes through are known and the jobs in the stations queues at any point are known. All of the other parameters associated with the flow shop, including job processing times per station, and station queuing behavior are uncertain though there is a significant body of past performance data that might be brought to bear. The objective, in this environment, is to meet the delivery date promised when the job is accepted. To attack the problem the author develops a novel heuristic algorithm for decomposing the WFMS's event logs exposing non-standard queuing behavior, develops a new simulation component to implement that behavior, and assembles a prototypical system to automate the required historical analysis and allow for on-demand due date quoting through the use of embedded discrete event simulation modeling. To attack the problem the author develops a novel heuristic algorithm for decomposing the WFMS's event logs exposing non-standard queuing behavior, develops a new simulation component to implement that behavior, and assembles a prototypical system to automate the required historical analysis and allow for on-demand due date quoting through the use of embedded discrete event simulation modeling. The developed software components are flexible enough to allow for both the analysis of past performance in conjunction with the WFMS's event logs, and on-demand analysis of new jobs entering the system. Using the proportion of jobs completed within the predicted interval as the measure of effectiveness, the author validates the performance of the system over six months of historical data and during live operations with both samples achieving the 90% service level targeted.

Master of Science / Department of Computing and Information Sciences / Gurdip Singh / Developing an optimal working environment and managing the of work load in an efficient manner are the major challenges for most businesses today. So, the importance of the workflow and workflow management in an organization is unquestionable. Many organizations use sophisticated systems to organize the workflows. One such workflow system based on a concise and powerful modeling language called “Yet Another Workflow Language” is YAWL. YAWL handles complex data, transformations, integration with organizational resources and Web Service integration. Workflow comprises of three main perspectives: control-flow, data and the resources. In Yawl, the control-flow and the data-flow are tightly coupled within the workflow enactment engine. But the resource perspective is provided by a discrete custom service called Resource Service. Administrative tools are provided using which the administrator has to manually select the resource (referred as participant) which needs to perform a particular task of the workflow. This project aims at developing a service which can automate the assignment of the tasks to the participants by using the Resource service which provides number of interfaces that expose the full functionality of the service. The application of this project with respect to Healthcare domain is presented. Healthcare domain is the one of the most demanding and yet critical business process. Hospitals face increasing pressure to both improve the quality of the services delivered to patients and to reduce costs .Hence there is significant demand on hospitals in regard to how the organization, execution, and monitoring of work processes is performed. Workflow Management Systems like YAWL offers a potential solution as they support processes by managing the flow of work.

Modern enterprise organisations rely on dynamic processes. Generally these processes cannot be modelled once and executed repeatedly without change. Enterprise processes may evolve unpredictably according to situations that cannot always be prescribed. However, no mechanism exists to ensure an updated process does not violate any compliance requirements. Typical workflow processes may follow a process definition and execute several thousand instances using a workflow engine without any changes. This is suitable for routine business processes. However, when business processes need flexibility, adaptive features are needed. Updating processes may violate compliance requirements so automatic verification of compliance checking is necessary. The research work presented in this Thesis investigates the problem of current workflow technology in defining, managing and ensuring the specification and execution of business processes that are dynamic in nature, combined with policy standards throughout the process lifycle. The findings from the literature review and the system requirements are used to design the proposed system architecture. Since a two-tier reference process model is not sufficient as a basis for the reference model for an adaptive and compliance workflow management system, a three-tier process model is proposed. The major components of the architecture consist of process models, business rules and plugin modules. This architecture exhibits the concept of user adaptation with structural checks and dynamic adaptation with data-driven checks. A research prototype - Adaptive and Compliance Workflow Management System (ACWfMS) - was developed based on the proposed system architecture to implement core services of the system for testing and evaluation purposes. The ACWfMS enables the development of a workflow management tool to create or update the process models. It automatically validates compliance requirements and, in the case of violations, visual feedback is presented to the user. In addition, the architecture facilitates process migration to manage specific instances with modified definitions. A case study based on the postgraduate research process domain is discussed.

<p>This paper gives an overview of workflow management systems (WfMSs) and their security requirements with focus on access mechanisms. It is a descriptive paper in which we examine the state of the art of workflow systems, describe what security risks affect WfMSs in particular, and how these can be diminiuished.</p><p>WfMSs manage, illustrate and support business processes. They contribute to the performance, automation and optimization of processes, which is important in the global economy today. The security of process flows is important, since the sensitive business data need to be protected to inhibit illegal activities, such as blackmailing, imitation and fraud and to provide for good customer service.</p><p>This paper focuses on access mechanisms, because they are basic security mechanisms used by WfMSs assuring that only authorized users are provided access to data and resources. Also because of the unsecurity of the Internet, which is commonly used as infrastructure of Workflow systems, additional security mechanisms, such as PKIs, digital signatures and SSL have to be used to provide secure workflows.</p><p>Depending on the particular requirements in workflow systems, different extensional access control (AC) mechanisms have been developed to maintain security. But when it comes to commercially used WfMSs, the availability of the system is of utmost importance. It is the prerequisite for the system to be employed by companies. The problem is that there is always a trade-off between availability of the system and security. Because this trade off is generally solved in favor of availability, a major part of the developed AC mechanisms are not used in commercially used WfMS.</p><p>After the first part of this paper which is rather theoretical, we examine a commercial WfMS, namely IBM's MQ Workflow , and its security mechanisms. We show vulnerabilities of the system that could be abused by attackers. Afterwards, we show which security mechanisms, in particular, AC mechanisms are provided to secure against threats. We conclude with a summary, which highlights the difference between security concepts developed in the research area and those really implemented by the commercially used WfMS.</p>

Microelectromechanical systems (MEMS) are miniaturized devices with high functionality. In recent years, MEMS products have become increasingly dominant in every aspect of the commercial market place. As the MEMS technology is in its infant stage and has several unique features compared to macro-scale products, it is faced with several challenges. One of them is that design and fabrication knowledge is very intrigue and thus very difficult to be accessible. An effective computer support to the MEMS product development is thus very important. This thesis study undertakes a thorough investigation into the MEMS product development process and its computer support. Specifically, the study examines the state-of-the-art in computer aided design systems in light of the support of product functionality. It is shown that MEMS product development involves high degree of uncertainty, which calls for an unconventional computer support. At this point, this study proposes an approach to construct a knowledge base in a fairly flexible and real-time manner. This approach is based on the extended function-behavior-structure framework and the template technique proposed in this thesis. The other finding is that the MEMS product development resembles the one-of-a-kind product (OKP) development. Therefore software tools for the OKP product development process can be applied to the MEMS product development process. These tools are examined, and further extensions upon them are proposed. Throughout the thesis, a microdispensing system is used as an example for illustration of concepts described in this thesis.