UseCase: NotifyUserOnCompletionOfWorkflowStep

UseCaseDescription:

The lab book wishes to display the current state of execution of a workflow (presumably one launched from the lab book). The workflow enactment engine will send out notifications such as 'Medline query started' or 'Workflow finished'. These are sent to the notification service allowing the user proxy, and any other interested parties, to subscribe to have the messages forwarded on to them.

The biologist starts a pre-provided Grave's disease experiment workflow. This could, for example, include an activity for searching for a gene homologous to a candidate gene using BLAST. When the activity has finished, a message saying "BLAST search complete" is sent to the user.

PrimaryActor:

A Biologist (see UserTaxonomy).

OtherActors:

SystemComponents:

Notification service, user proxy, workflow enactment engine, lab book

DomainAssumptions:

User proxy able to receive notifications and affect a lab book in an appropriate manner. Notification service able to push notifications to another web service.

PreConditions:

Topic for job status notifications mutually known by user proxy and enactment engine. The enactment engine also needs an identity, known to the user proxy, so that the user proxy can state that it is interested in the job status of only that enactment.

FlowOfEvents:

1. User creates enactment engine via lab book, gateway
2. User proxy gets enactment engine's ID from enactment engine
3. User proxy gets job status topic name from workflow definition
4. User proxy subscribes (as a push subscriber) to notifications on the given topic where the publisher is identified by the enactment engine ID
5. User proxy starts the workflow enactment providing the endpoint of the notification service used as input
6. By enacting the workflow definition, the engine registers as a publisher to the given notification service
7. After each activity is completed, the engine (by enacting the workflow) sends a notification on the job status topic
8. Each notification is received by the user proxy
9. The current job status is extracted from the notifications and displayed on the lab book

EndResult:

A sequence of messages on the lab book showing the workflow enactment status (possibly overwriting each other).

PostConditions:

Enactment complete, "Workflow Complete" or something similar displayed on lab book.

DevelopmentSteps:

• Notification service able to push notifications to push subscribers
• User proxy able to register and receive notifications as push subscriber
• Enactment engine separates creation and enactment stages
• Enactment engine able to return own ID
• Enactment engine able to use ID as parameter in web service calls
• User proxy able to discover topic name from workflow definition
• Enactment engine able to take endpoint of a web service to be called as input
• Lab book able to display job status on notification

DevelopmentLevel:

Weak (all this functionality should work stabley eventually, and the push subscription model should be developed stabley in the notification service and user proxy by July).

KeyReferences:

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Links to UserInterviews, FreeTextCases, LiteratureCases and ScientificProblems:

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Notes:

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Discussion:

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-- SimonMiles - 19 Feb 2003