HUMAN TASK INTEGRATION IN WEB BASED BUSINESS PROCESSES

A Groundwork Investigation

Xue Bai COMS E6125 WEB-ENHANCED INFORMATION MGMT

Outline

Business Process Execution Language,

BPEL4People, WS-HumanTask

Open problem

Potential Directions

WS-BPEL

Web Services Business Process Execution

Language Executable workflow language Define formal specification of the “Business Processes” or

“Workflows”

It’s the combination of WSFL and XLANG Standards:

http://docs.oasis-open.org/wsbpel/2.0/wsbpel-v2.0.pdf

Drawback: lack of “human workflow” support,

human interactions are not defined

BPEL4People

WS Business Process Execution Language for People

To address human interactions in BPEL by defining a new type of basic activity which uses human tasks as an implementation

This extension is based on the WS-HumanTask specification, as a bridge

between BPEL and WS-HT Specification: BPEL4People White Paper: BPEL4People

WS-HumanTask

Introduces the definition of human tasks, including their properties, behaviors and a set of operations used to manipulate human tasks

human tasks are services which are implemented by people so as to allow the integration of humans in service-oriented application

Specification: WS-HumanTask

BPEL4People

The relationship among the various standards to support the BPEL4People

Web services standards hierarchy

BPEL4People: An Introductory Tutorial

People activity, WS-HT specifies a human task

BPEL4People: An Introductory Tutorial

A business process, a sequence of BPEL activities

BPEL4People: An Introductory Tutorial

Workflow in a graph view

Open Problems

Significant difference: Unpredictable nature of human activities

Create a simple process to finish a business loan request to show scenario

Open Problems

2 Companies, 2 Human Tasks, 4 Web Services Exchange information and services, 9 steps

LoanRepresentative:

Tom

Loan request invoke

Information

RiskEvaluationRepresentative:

Cathy

RiskEvaluationReport

decision

result

Information

invoke

RiskEvaluationReport request

EndUer:

Peter

Open Problems

Two alternate case scenarios in step 7 (results)

Risk evaluation representative “Cathy” may need more information of end user “Peter”, report

“Cathy” may find some mistakes about the information from “Peter”, and she wants the “Loan Company”, to check the information again

Peter

Tom

Cathy

Potential Directions

Professional process design Avoid breaking down in the business process

Humans involved in the business process can communicate with each other In the example described above, if “Cathy” finds some

problems about the information provided by the “Loan Company”, she may contact the last human role in the business, “Tom” in this case

Potential Directions

Introduce the role of a “Proxy” Monitor the data transmissions between web services If a process needs to restart at some point other than the

beginning, a copy of the data which is the input at that point will be delivered or coordinated from the “Proxy”

Thanks!