To create a custom workflow process it's highly recommend that you use the Eclipse BPMN2 Modeler plugin available in the Eclipse marketplace.
- Custom Workflow Guide shows how to add human tasks to a workflow.
- Custom Workflow WorkItem Handler shows how to add automated work items to a workflow.
You can implement a simple 4-eye publishing workflow with tasks. You don't need the Workflow module or jBPM unless your workflow is more complex, involving three participants or rejection.