4.10. Bibliographical Notes
If you are involved in design or architecture as well as specification, you will now benefit immensely from reading Michael Havey's (2005) superb introduction to the more technical aspects of BPM. It goes into much more detail on the syntax of BPEL and WS-CDL and contains an excellent layman's introduction to pi-calculus and Petri nets. I cannot recommend it enough - although the version numbers have moved on a little since it was published. Perhaps there will be a second edition by the time this text hits the streets. I hope so.
Ross (2005) provides an interesting classification of business rules in relation to business process management, saying that there are three important categories: rules at decision points, rules at rejection points and process coördination rules. Decision points typically involve an organization's particular expertise and might include such things as medical diagnosis, paying an insurance claim or detecting a fraud. Businesses cannot be modelled without considering such rules. Rules at rejection points are merely constraints on possible decisions, e.g. you can't marry someone under sixteen. Process co-ordination rules are there to ensure that processes run properly. In an SOA these are especially important because that may determine message routing and filtering. Ross also makes a very good case for combining business process management and business rules management. Graham (2006) provides an introduction to the latter.