Leonid Mamchenkov has put together a post for those out there trying to get started with workflows in PHP and offers some tips from his own experience.
For a large project at work, we need to integrate or develop a workflow engine. I worked a little bit with workflow engines in the past, but the subject is way to big and complex for me to claim any expertise in it.
So, I am looking at what’s available these days and what are our options. This post is a collection of initial links and thoughts, and it’s goal is mostly to document my research process and findings, and not to provide any answers or solutions yet.
He starts off by defining the requirements of the system he's looking for, both on the technology side and the functional side. He outlines his expected flow and then links to some other resources he found to help define common terminology and some of the standards he found. He found the BPMN v2.0 and tracked down several PHP packages that implement that workflow structure (all linked as well).