Can WWF handle high throughput scenarios where several dozen records are 'actively' being processed in parallel at any one time? We want to build a workflow process which handles a few thousand records per hour. Each record takes up to a minute to process, because it makes external web service calls. We are testing Windows Workflow Foundation to do this. But our demo programs show processing of each record appear to be running in sequence not in parallel, when we use parallel activities to process several records at once within one workflow instance. Should we use multiple workflow instances or parallel activities? Are there any known patterns for high performance WWF processing?