22 research outputs found
CrowdCE: A Collaboration Model for Crowdsourcing Software with Computing Elements
Todayâs crowd computing models are mainly used for handling independent tasks with simplistic collaboration and coordination through business workflows. However, the software development processes are complex, intellectually and organizationally challenging business models. We present a model for software development that addresses key challenges. It is designed for the crowd in the development of a social application. Our model presents an approach to structurally decompose the overall computing element into atomic machine-based computing elements and human-based computing elements such that the elements can complement each other independently and socially by the crowd. We evaluate our approach by developing a business application through crowd work. We compare our model with the traditional software development models. The primary result was completed well for empowering the crowd
A standards-based ICT framework to enable a service-oriented approach to clinical decision support
This research provides evidence that standards based Clinical Decision Support (CDS)
at the point of care is an essential ingredient of electronic healthcare service delivery. A
Service Oriented Architecture (SOA) based solution is explored, that serves as a task
management system to coordinate complex distributed and disparate IT systems,
processes and resources (human and computer) to provide standards based CDS.
This research offers a solution to the challenges in implementing computerised CDS such
as integration with heterogeneous legacy systems. Reuse of components and services to
reduce costs and save time. The benefits of a sharable CDS service that can be reused by
different healthcare practitioners to provide collaborative patient care is demonstrated.
This solution provides orchestration among different services by extracting data from
sources like patient databases, clinical knowledge bases and evidence-based clinical
guidelines (CGs) in order to facilitate multiple CDS requests coming from different
healthcare settings. This architecture aims to aid users at different levels of Healthcare
Delivery Organizations (HCOs) to maintain a CDS repository, along with monitoring and
managing services, thus enabling transparency.
The research employs the Design Science research methodology (DSRM) combined with
The Open Group Architecture Framework (TOGAF), an open source group initiative for
Enterprise Architecture Framework (EAF). DSRMâs iterative capability addresses the
rapidly evolving nature of workflows in healthcare. This SOA based solution uses
standards-based open source technologies and platforms, the latest healthcare standards
by HL7 and OMG, Decision Support Service (DSS) and Retrieve, Update Locate Service
(RLUS) standard. Combining business process management (BPM) technologies,
business rules with SOA ensures the HCOâs capability to manage its processes. This
architectural solution is evaluated by successfully implementing evidence based CGs at
the point of care in areas such as; a) Diagnostics (Chronic Obstructive Disease), b) Urgent
Referral (Lung Cancer), c) Genome testing and integration with CDS in screening
(Lynchâs syndrome). In addition to medical care, the CDS solution can benefit
organizational processes for collaborative care delivery by connecting patients,
physicians and other associated members. This framework facilitates integration of
different types of CDS ideal for the different healthcare processes, enabling sharable CDS
capabilities within and across organizations
Optimizing performance of workflow executions under authorization control
âBusiness processes or workflows are often used to
model enterprise or scientific applications. It has
received considerable attention to automate workflow
executions on computing resources. However, many
workflow scenarios still involve human activities and
consist of a mixture of human tasks and computing
tasks.
Human involvement introduces security and
authorization concerns, requiring restrictions on who
is allowed to perform which tasks at what time. Role-
Based Access Control (RBAC) is a popular authorization
mechanism. In RBAC, the authorization concepts such as
roles and permissions are defined, and various
authorization constraints are supported, including
separation of duty, temporal constraints, etc. Under
RBAC, users are assigned to certain roles, while the
roles are associated with prescribed permissions.
When we assess resource capacities, or evaluate the
performance of workflow executions on supporting
platforms, it is often assumed that when a task is
allocated to a resource, the resource will accept the
task and start the execution once a processor becomes available. However, when the authorization policies
are taken into account,â this assumption may not be
true and the situation becomes more complex. For
example, when a task arrives, a valid and activated
role has to be assigned to a task before the task can
start execution. The deployed authorization
constraints may delay the workflow execution due to
the rolesâ availability, or other restrictions on the
role assignments, which will consequently have
negative impact on application performance.
When the authorization constraints are present to
restrict the workflow executions, it entails new
research issues that have not been studied yet in
conventional workflow management. This thesis aims to
investigate these new research issues.
First, it is important to know whether a feasible
authorization solution can be found to enable the
executions of all tasks in a workflow, i.e., check the
feasibility of the deployed authorization constraints.
This thesis studies the issue of the feasibility
checking and models the feasibility checking problem
as a constraints satisfaction problem.
Second, it is useful to know when the performance of
workflow executions will not be affected by the given
authorization constraints. This thesis proposes the
methods to determine the time durations when the given
authorization constraints do not have impact.
Third, when the authorization constraints do have
the performance impact, how can we quantitatively
analyse and determine the impact? When there are multiple choices to assign the roles to the tasks,
will different choices lead to the different
performance impact? If so, can we find an optimal way
to conduct the task-role assignments so that the
performance impact is minimized? This thesis proposes
the method to analyze the delay caused by the
authorization constraints if the workflow arrives
beyond the non-impact time duration calculated above.
Through the analysis of the delay, we realize that the
authorization method, i.e., the method to select the
roles to assign to the tasks affects the length of the
delay caused by the authorization constraints. Based
on this finding, we propose an optimal authorization
method, called the Global Authorization Aware (GAA)
method.
Fourth, a key reason why authorization constraints
may have impact on performance is because the
authorization control directs the tasks to some
particular roles. Then how to determine the level of
workload directed to each role given a set of
authorization constraints? This thesis conducts the
theoretical analysis about how the authorization
constraints direct the workload to the roles, and
proposes the methods to calculate the arriving rate of
the requests directed to each role under the role,
temporal and cardinality constraints.
Finally, the amount of resources allocated to
support each individual role may have impact on the
execution performance of the workflows. Therefore, it
is desired to develop the strategies to determine the
adequate amount of resources when the authorization
control is present in the system. This thesis presents the methods to allocate the appropriate quantity for
resources, including both human resources and
computing resources. Different features of human
resources and computing resources are taken into
account. For human resources, the objective is to
maximize the performance subject to the budgets to
hire the human resources, while for computing
resources, the strategy aims to allocate adequate
amount of computing resources to meet the QoS
requirements
Knowledge-base and techniques for effective service-oriented programming & management of hybrid processes
Recent advances in Web 2.0, SOA, crowd-sourcing, social and collaboration technologies, as well as cloud-computing, have truly transformed the Internet into a global development and deployment platform. As a result, developers have been presented with ubiquitous access to countless Web-services, resources and tools. However, while enabling tremendous automation and reuse opportunities, new productivity challenges have also emerged: The exploitation of services and resources nonetheless requires skilled programmers and a development-centric approach; it is thus inevitably susceptible to the same repetitive, error-prone and time consuming integration work each time a developer integrates a new API.
Business Process Management on the other hand were proposed to support service-based integration. It provided the benefit of automation and modelling, which appealed to non-technical domain-experts. The problem however: it proves too rigid for unstructured processes. Thus, without this level of support, building new application either requires extensive manual programming or resorting to homebrew solutions. Alternatively, with the proliferation of SaaS, various such tools could be used for independent portions of the overall process - although this either presupposes conforming to the in-built process, or results in "shadow processes" via use of e-mail or the like, in order to exchange information and share decisions. There has therefore been an inevitable gap in technological support between structured and unstructured processes.
To address these challenges, this thesis deals with transitioning process-support from structured to unstructured. We have been motivated to harness the foundational capabilities of BPM for its application to unstructured processes. We propose to achieve this by: First, addressing the productivity challenges of Web-services integration - simplifying this process - whilst encouraging an incremental curation and collective reuse approach. We then extend this to propose an innovative Hybrid-Process Management Platform that holistically combines structured, semi-structured and unstructured activities, based on a unified task-model that encapsulates a spectrum of process specificity. We have thus aimed to bridge the current lacking technology gap.
The approach presented has been exposed as service-based libraries and tools. Whereby, we have devised several use-case scenarios and conducted user-studies in order to evaluate the overall effectiveness of our proposed work
A service oriented architecture to implement clinical guidelines for evidence-based medical practice
Health information technology (HIT) has been identified as the fundamental driver to streamline the healthcare delivery processes to improve care quality and reduce operational costs. Of the many facets of HIT is Clinical Decision Support (CDS) which provides the physician with patient-specific inferences, intelligently filtered and organized, at appropriate times. This research has been conducted to develop an agile solution to Clinical Decision Support at the point of care in a healthcare setting as a potential solution to the challenges of interoperability and the complexity of possible solutions. The capabilities of Business Process Management (BPM) and Workflow Management systems are leveraged to support a Service Oriented Architecture development approach for ensuring evidence based medical practice. The aim of this study is to present an architecture solution that is based on SOA principles and embeds clinical guidelines within a healthcare setting. Since the solution is designed to implement real life healthcare scenarios, it essentially supports evidence-based clinical guidelines that are liable to change over a period of time.
The thesis is divided into four parts. The first part consists of an Introduction to the study and a background to existing approaches for development and integration of Clinical Decision Support Systems. The second part focuses on the development of a Clinical Decision Support Framework based on Service Oriented Architecture. The CDS Framework is composed of standards based open source technologies including JBoss SwitchYard (enterprise service bus), rule-based CDS enabled by JBoss Drools, process modelling using Business Process Modelling and Notation. To ensure interoperability among various components, healthcare standards by HL7 and OMG are implemented. The third part provides implementation of this CDS Framework in healthcare scenarios. Two scenarios are concerned with the medical practice for diagnosis and early intervention (Chronic Obstructive Pulmonary Disease and Lung Cancer), one case study for Genetic data enablement of CDS systems (New born screening for Cystic Fibrosis) and the last case study is about using BPM techniques for managing healthcare organizational perspectives including human interaction with automated clinical workflows. The last part concludes the research with contributions in design and architecture of CDS systems.
This thesis has primarily adopted the Design Science Research Methodology for Information Systems. Additionally, Business Process Management Life Cycle, Agile Business Rules Development methodology and Pattern-Based Cycle for E-Workflow Design for individual case studies are used. Using evidence-based clinical guidelines published by UKâs National Institute of Health and Care Excellence, the integration of latest research in clinical practice has been employed in the automated workflows. The case studies implemented using the CDS Framework are evaluated against implementation requirements, conformance to SOA principles and response time using load testing strategy.
For a healthcare organization to achieve its strategic goals in administrative and clinical practice, this research has provided a standards based integration solution in the field of clinical decision support. A SOA based CDS can serve as a potential solution to complexities in IT interventions as the core data and business logic functions are loosely coupled from the presentation. Additionally, the results of this this research can serve as an exemplar for other industrial domains requiring rapid response to evolving business processes
Coordinating Service Compositions : Model and Infrastructure for Collaborative Creation of Electronic Documents
Electronic documents frequently include contributions from different human and non-human sources. The Web, for instance, offers ever-changing content and services which can perform activities during document creation. This thesis introduces a solution for collaborative document creation which maps contributions of human and non-human participants to software services. The joint flexible composition and coordination of these services leads to a novel understanding of dynamic Web-based documents
Self-managed Workflows for Cyber-physical Systems
Workflows are a well-established concept for describing business logics and processes in web-based applications and enterprise application integration scenarios on an abstract implementation-agnostic level. Applying Business Process Management (BPM) technologies to increase autonomy and automate sequences of activities in Cyber-physical Systems (CPS) promises various advantages including a higher flexibility and simplified programming, a more efficient resource usage, and an easier integration and orchestration of CPS devices. However, traditional BPM notations and engines have not been designed to be used in the context of CPS, which raises new research questions occurring with the close coupling of the virtual and physical worlds. Among these challenges are the interaction with complex compounds of heterogeneous sensors, actuators, things and humans; the detection and handling of errors in the physical world; and the synchronization of the cyber-physical process execution models. Novel factors related to the interaction with the physical world including real world obstacles, inconsistencies and inaccuracies may jeopardize the successful execution of workflows in CPS and may lead to unanticipated situations.
This thesis investigates properties and requirements of CPS relevant for the introduction of BPM technologies into cyber-physical domains. We discuss existing BPM systems and related work regarding the integration of sensors and actuators into workflows, the development of a Workflow Management System (WfMS) for CPS, and the synchronization of the virtual and physical process execution as part of self-* capabilities for WfMSes. Based on the identified research gap, we present concepts and prototypes regarding the development of a CPS WFMS w.r.t. all phases of the BPM lifecycle. First, we introduce a CPS workflow notation that supports the modelling of the interaction of complex sensors, actuators, humans, dynamic services and WfMSes on the business process level. In addition, the effects of the workflow execution can be specified in the form of goals defining success and error criteria for the execution of individual process steps. Along with that, we introduce the notion of Cyber-physical Consistency. Following, we present a system architecture for a corresponding WfMS (PROtEUS) to execute the modelled processes-also in distributed execution settings and with a focus on interactive process management. Subsequently, the integration of a cyber-physical feedback loop to increase resilience of the process execution at runtime is discussed. Within this MAPE-K loop, sensor and context data are related to the effects of the process execution, deviations from expected behaviour are detected, and compensations are planned and executed. The execution of this feedback loop can be scaled depending on the required level of precision and consistency. Our implementation of the MAPE-K loop proves to be a general framework for adding self-* capabilities to WfMSes. The evaluation of our concepts within a smart home case study shows expected behaviour, reasonable execution times, reduced error rates and high coverage of the identified requirements, which makes our CPS~WfMS a suitable system for introducing workflows on top of systems, devices, things and applications of CPS.:1. Introduction 15
1.1. Motivation 15
1.2. Research Issues 17
1.3. Scope & Contributions 19
1.4. Structure of the Thesis 20
2. Workflows and Cyber-physical Systems 21
2.1. Introduction 21
2.2. Two Motivating Examples 21
2.3. Business Process Management and Workflow Technologies 23
2.4. Cyber-physical Systems 31
2.5. Workflows in CPS 38
2.6. Requirements 42
3. Related Work 45
3.1. Introduction 45
3.2. Existing BPM Systems in Industry and Academia 45
3.3. Modelling of CPS Workflows 49
3.4. CPS Workflow Systems 53
3.5. Cyber-physical Synchronization 58
3.6. Self-* for BPM Systems 63
3.7. Retrofitting Frameworks for WfMSes 69
3.8. Conclusion & Deficits 71
4. Modelling of Cyber-physical Workflows with Consistency Style Sheets 75
4.1. Introduction 75
4.2. Workflow Metamodel 76
4.3. Knowledge Base 87
4.4. Dynamic Services 92
4.5. CPS-related Workflow Effects 94
4.6. Cyber-physical Consistency 100
4.7. Consistency Style Sheets 105
4.8. Tools for Modelling of CPS Workflows 106
4.9. Compatibility with Existing Business Process Notations 111
5. Architecture of a WfMS for Distributed CPS Workflows 115
5.1. Introduction 115
5.2. PROtEUS Process Execution System 116
5.3. Internet of Things Middleware 124
5.4. Dynamic Service Selection via Semantic Access Layer 125
5.5. Process Distribution 126
5.6. Ubiquitous Human Interaction 130
5.7. Towards a CPS WfMS Reference Architecture for Other Domains 137
6. Scalable Execution of Self-managed CPS Workflows 141
6.1. Introduction 141
6.2. MAPE-K Control Loops for Autonomous Workflows 141
6.3. Feedback Loop for Cyber-physical Consistency 148
6.4. Feedback Loop for Distributed Workflows 152
6.5. Consistency Levels, Scalability and Scalable Consistency 157
6.6. Self-managed Workflows 158
6.7. Adaptations and Meta-adaptations 159
6.8. Multiple Feedback Loops and Process Instances 160
6.9. Transactions and ACID for CPS Workflows 161
6.10. Runtime View on Cyber-physical Synchronization for Workflows 162
6.11. Applicability of Workflow Feedback Loops to other CPS Domains 164
6.12. A Retrofitting Framework for Self-managed CPS WfMSes 165
7. Evaluation 171
7.1. Introduction 171
7.2. Hardware and Software 171
7.3. PROtEUS Base System 174
7.4. PROtEUS with Feedback Service 182
7.5. Feedback Service with Legacy WfMSes 213
7.6. Qualitative Discussion of Requirements and Additional CPS Aspects 217
7.7. Comparison with Related Work 232
7.8. Conclusion 234
8. Summary and Future Work 237
8.1. Summary and Conclusion 237
8.2. Advances of this Thesis 240
8.3. Contributions to the Research Area 242
8.4. Relevance 243
8.5. Open Questions 245
8.6. Future Work 247
Bibliography 249
Acronyms 277
List of Figures 281
List of Tables 285
List of Listings 287
Appendices 28