Eb Workflow Agents

chances are you're engaged in a work-flow. Even when you're doing non-computer work—for example, ordering parts for your project or factory by telephone, or calling an airline or a government office—you are most likely participating unwittingly in a workflow. A workflow is a composite activity consisting of tasks involving a number of humans, databases, and specialized applications. The component tasks are related and share various control, data, and temporal dependencies. A classic example of a workflow is loan processing: When you apply for a loan, you fill out a form, a clerk reviews it for completeness , an auditor verifies the information , and a supervisor invokes an external credit agency or uses a credit risk assessment tool. Each person in the loan process receives information concerning your application, modifies or adds to it, and forwards the results. Another example, illustrated in Figure 1, is when you order a service from a telecommunications provider. You initiate the order by interacting with a sales representative from the provider, who fills out a form on your behalf. The sales representative checks with a provisioning database to determine whether the necessary hardware is in place. If it is, you receive an estimate of when the service will be ready for your use. A local service installer is dispatched to install your service while the telecommunications provider checks your credit history. If all goes well, the installer successfully installs the service, the auditors find your credit history acceptable, the billing department is notified to begin charging you, and the workflow concludes successfully. Murphy's Law However, things don't always go that smoothly. For example, in checking whether you already have an account, the telecommunications provider might discover that you have an unpaid and overdue balance—or that someone else previously at the same address has an unpaid balance. Such discoveries would raise a red flag. Perhaps the service installer for your area calls in sick, requiring a revision in the installation schedule. Or the installer might discover that the available hardware is unusable and must be replaced. Each of these situations can lead to modified behavior, as illustrated in Figure 2. Such modifications might lead to an additional change in schedule or possibly even cause you to cancel the order altogether because you don't want to wait indefinitely. These occurrences are instances of exceptions that can arise during work-flow execution. The number of possible exceptions is …