Information Technology Reference
In-Depth Information
research and development. Here, we discuss a few open and exciting issues
in this field.
9.1 WORKFLOWS IN HOSTING PLATFORMS
The success of cloud computing has put the SaaS (software as a service)
model in the ascendant. SaaS is a software delivery model in which
application and associated data are hosted on the cloud, and users access
the software using a thin client such as a Web browser. Hosting
workflow systems using SaaS has several advantages. First, like any
other middleware, workflow management systems are complex to
design, deploy, and manage; moreover, they need to scale out to
cope with sudden workload surge. These features make it desirable
to provision a workflow system in a SaaS manner.
Second, a benefit that is specific to workflow is that workflow-as-a-
service can enable the sharing of best practices. Current approaches to
service composition are generally used in isolated standalone applica-
tions. Developers cannot leverage any existing knowledge, and the
experience they have gained through the composition practice is neither
accumulated nor shared among people who undertake similar tasks.
Think of this alternative: in a hosted workflow platform when users are
to compose a new workflow, they can see similar workflows already
completed and contributed by others. During composition, they can get
context-aware assistance such as which services to use,
in what
sequence, and even whom to consult for questions.
Third, SaaS has been the model for many enterprise software pack-
ages/tools such as CRM and ERP, while the workflow technology is
usually embedded in them. The trend to run workflows in hosting
platforms such as cloud is also triggered by business process outsourcing
(BPO) where the operations of specific business processes are outsourced
to a third-party service provider. Nowadays, such workflow systems are
provided by major vendors such as Amazon, Salesforce, and IBM.
We would like to envision the future of hosted workflow systems by
making an analogy to Apple's App Store that is arguably the most
successful business mode in IT industry nowadays. In App Store users
browse and shop various applications, download and use them in devices
such as iPhone and iPad. These applications when in use usually need to
access cloud-hosted data (contents to be delivered to users, such as user
