CONTENTS Arrival Characters Definition Merits Chararterstics Workflows Wfms Workflow engine Workflows levels & categories

INTRODUCTION ARRIVAL : Parrallel computing Distributed computing Grid computing Public computing SAAS

CHARACTERS : Virtualization : nothing to do with physical platforms Distribution : refers to the physical node which the computation uses is distributed Dynamically extendibility : refers to through the dynamic extension virtualization level, then achieves to above applies carries on the expansion the goal.

Cloud Computing : Delivering applications or services in on-demand environment Hundreds of thousands of users / applications Systems should be fast, secure and available Intelligent infrastructure: Transparency Scalability Monitoring Security All services and associated data

Merits : It provides a mandatory application program environment. a distributed foundation establishment, and monitor the distributed system, to achieve the purpose of efficient use of the system. it integrates the history data and present data to make the collected information more accurate and provide more intelligent service for users and enterprises.

cloud computing is easy to extend, and has an simple management style. supports for SAAS(software as a Service). The aim of application of cloud computing is to combine all the resources, and let anyone can use it.

Charaterstics of cloud computing : Ultra large scale Virtualization High reliability Versatility High extendibility On demand service Extremely inexpensive

WORKFLOW : “The automation of a business process, in whole or parts, where documents, information or tasks are passed from one participant to another to be processed, according to a set of procedural rules “

Workflows : Operational aspect of a work procedure: how tasks are structured, who performs them, what their relative order is, how they are synchronized, how information flows to support the tasks and how tasks are being tracked.

Workflow Management System (WFMS) “A system that defines, creates and manages the execution of workflows through the use of software, running on one or more workflow engines, which is able to interpret the process definition, interact with workflow participants and, where required, invoke the use of IT tools and applications.” Workflow Engine “A software service or "engine" that provides the run time execution environment for a process instance.”

WORKFLOWS LEVELS : Inside domain One unit/organization/Virtual Organization Level Up Above Multiple Virtual Organizations Global Model More dynamic More Grid … Global Model Global Process Peer-To-Peer Orchestration … Choreography …

Categories of workflows : Collaborative Production Ad Hoc Administrative

Workflow Lifecycle : Design Typical workflow is graph oriented Language: how expressive is workflow GUI: Visual Service Composition Environment Deployment Workflow Description is sent to Workflow Engine Possibly validated and compiled Execution Workflow Engine enacts Workflow Description Monitoring Events reflecting from workflow and services execution Refinement

Workflow Usage Concerns : Constructs supported Expressiveness of Programming Language Ease of creation and modification by non programmers (GUI) Extensibility Ease of Integration Support for Standards Support for Web Services Support for Grid, GT2, OGSI Ease of Use (Very subjective …) Status, Availability Licensing, Price

Workflow Mangement : An activity is a discrete step in a business process (workflow). Activities range from calling a remote service to perform a task, e.g. calculating taxes, performing currency conversions, looking up inventory, to custom-defined services. Activities are orchestrated together in a workflow in BizTalk using XOML (eXtensible Object Markup Language). Other languages BPEL, ebXML, XPDL etc.