1. A method of creating a processing job, the method comprising: creating a chain, the chain being a group of interrelated tasks to be performed; associating the group of tasks with a plurality of steps, each step occupying a position in the chain, each task being capable of associating with multiple steps in one or more chains; creating a set of rules interrelating the steps, each rule comprising a condition and an action, the condition describing a prerequisite for performing the action; and creating a job for the chain.