: "Difference between Workflow and Rule engines
There are some blurry lines here. My quick answer is:
Workflow - typically a flow of information and actions associated with people. This term became popular 15-20 years ago with things like expense report approvals, or imaging systems that would route things like credit card receipts and problems to different people to take action on rather than sending paper around with a sign-off sheet on top.
BPM - Business Process Management. This term became popular over the past 5-10 years and typically refers to a combination of people and system oriented processes. So say someone approves an expense report, but then it kicks off a series of actions in several systems like payroll and general ledger.
BPM Engine - keeps track of the state of various items as they pass thru a graph of tasks and actions. Think of drawing a typical flow chart where the BPM engine keeps track of each items flowing thru the flow chart. Go to http://www.jbpm.org for some good overview docs and pointers.
Rules Engine - allows for complex set of rules to be applied to a complex set of data to make decisions. From the http://www.drools.org web site: 'Rule Engines and expert systems are a great way to collect complex decision-making logic and work with data sets too large for humans to effectively use. Rule engines can make decisions based on hundreds of thousands of facts, quickly, reliably and repeatedly.'"