Quite interesting that this just been posted.

I have to produce an events application with a UI similar to this: http://i.imgur.com/e0R1Kp5.png

The UI is already done, so that's not the reason for the post.

My question is, on the backend, is there a pattern I can use to easily execute the steps?

I know there is a combination of logic, cron, a MQ and a db to hold the flow. But I am unsure on how best to approach the development of this framework.

Probably if someone is passing by and you've built something like this. I'd love your input as I'm a bit unsure how to proceed.

I'd really like best practice and implement something that is robust!

Thanks