Software developers have been implementing workflows to model business processes since the beginning of time. During this time, we've learned that workflows can be long-running and often require input from humans. Building a robust workflow to meet these challenges is a daunting task. An ideal paradigm for building workflows is to separate the workflow definition from the engine that executes the workflow.
Once we've separated workflow definitions from the execution engine, we can go on to build workflow components to create a domain‑specific language. A businessperson has the ability to understand the domain‑specific language, and can understand a workflow without seeing the clutter of exception handling and workflow tracking.
Windows Workflow brings a workflow engine and workflow development tools to Microsoft platforms. The instructions for the WF engine are activities, and we can arrange these activities using a graphical designer, XAML, code, or a combination of the three. WF provides the services we need for a workflow engine, including persistence, threading, and transaction services. The future looks bright for building workflow solutions.