The current user experience in Jenkow plugin is such that.

1. you create a new job, specifying a non-existent workflow name
2. you run the build once, make it fail (this is when the plugin internally creates a skeleton workflow file)
3. you checkout the newly created bpmn file, and edit it.

This idea of inducing a failure to have it created it is bit strange, and it also has an undesirable side-effect that if you have a typo in the workflow name, you end up creating one.

I think a better user experience is:

1. you create a new job, specifying a non-existent workflow name
2. form validation gives you a button/link that lets you create new template workflow files (or copy from existing one, which is likely useful, too) see Subversion plugin for how it does this, when the user types in a repository URL for which it doesn't yet have a credential.