The agenda for the OMG Business Rules Standards Symposium in June has been published: it covers a wide gamut of business-related rule standards/standards-in-progress from BMM (motivations, policies), through to SBVR (documentation/formalisation), PRR (production rule models for BREs) and DMN (decision models), then W3C RIF (rule interchange) and OWL (ontology).

From an event processing perspective, the domains of “decisioning in event processing” and “business rules” certainly overlap somewhat. TIBCO BusinessEvents Decision Manager, for example, provides managed decisions that are driven by event detection (and is one of the most recent “rule management” introductions from a major software vendor).

Business rule standards can impact a number of touchpoints in event processing, as we covered in a presentation to the Dagstuhl workshop, such as:

• BMM: define the strategy and policies that an event processing system should assist with
• SBVR: defines the business ontology / vocabulary, and associated business constraints, against which events are matched and applied respectively
• DMN: defines the decisions used in processes to support policies in event-driven applications
• PRR: defines the production rules, optionally event-driven, used to represent policy, business rule and decision logic
• RIF: defines the interchange format for rules representing basic logic, or even production rules and ECA rules

The standards community for the “rules and decisions” domain is still quite small compared to the impact such decisions and rules have in general IT - just think how many business rules direct BPM design, or how many decisions are made in BPM systems. Major vendors cooperating in the standards efforts include both IBM and TIBCO; FICO recently rejoined the PRR effort and Oracle is contributing to RIF. Perhaps the time for standards has come!

Disclosure: TIBCO is contributing the presentation on Production Rules and Decisioning.

OMG convened in the murder capital of Florida this week, possibly to add some excitement to the normally dour world of IT standards. There are, as we have recorded before, a number of ongoing standards initiatives that are relevant to event processing, with 2 in particular at OMG in progress:

- PRR (the Production Rule Representation) currently at version 1.0 and working towards a 1.1 tidy-up; ECA rules can be covered under PRR, although the current scope is not event-specific [*1]
- DMN (the Decision Modelling Notation), currently starting up as an initiative [*2].

This week DMN took a significant step forward in the standards process, when it gained as a supporter the world’s foremost “decision table” expert, Jan Vanthienen from Katholieke Universiteit Leuven in Belgium. Jan presented “decision tables” to the OMG’s Business Modelling and Integration group.

Jan explained how “decision tables” are just another representation of business rules, enabling completeness (every possibly input combination is covered) and exclusivity (every possibly input has ony 1 possible outcome associated with it) constraints to be enforced.

Decision Tables can also be used in several ways: from an IT perspective we tend to view them as an executable decision service (given inputs, determine a decision output). However, they can also be used in a goal-driven way: what input is needed to achieve a particular output. For the CEP community, of course, the “implicit invocation event” can be an explicit table condition…

There are several variations in decision tables defined as models, too: the most useful for business analysis is the one that defines all outputs as binary (boolean) results and it effectively is a lookup for outputs against inputs. Again, in IT systems these are normally truncated to a form where the output is the appropriate *action* (value being updated to some expression).

As one who has been preaching decision tables for many years, Jan has a number of reasons why people should use decision tables as a business rule representation for decisions:
- compact but powerful visualisation
- easy to verify (check) to avoid errors
- modular, compatible with hierarchies of decisions
- easy to make fast and efficient execution engines.

As an example, Jan used some text from a sports page on predicting some sportsperson’s tennis ranking based on the possible outcomes for the some future tournament results. Placing this logic in a decision table allowed the outcomes to be easily seen, and the specification inputs (what Jan calls business rule specifications) to be analysed for completeness and contradictions. As such it could be thought that a decision table approach contrasts with use of the OMG SBVR standard (Semantics of Business Vocabulary and Rules), where one defines business terms and constraint rules in a formal, well defined fashion. However it seems that in reality decision tables complement SBVR by providing a structured mechanism for defining fragments of SBVR terms and rules as used in decisions, and combining general rules, exceptions, modalities and timings.

So, effectively, a Decision Table is a relation between states and possible outcomes.

The methodology for defining decisions based on decision tables - a type of decision modelling - is well covered in a particular way by KPI’s book “The [KPI] Decision Model” [*3]. But the process is similar:
1 - interactive exploration of exceptions
2 - starting from text, built up possibilities and populate table

And in an “ease of use survey” Jan undertook, they found a strong preference for tables over trees,  and the same for trees over text, for a sample complex rulebase.

Notes:

*1 = TIBCO BusinessEvents uses inference rule agents that exploit production rules for identifying event patterns and making inferences.

*2 = TIBCO BusinessEvents includes decision table modelling and deployment, for decisions and reactions post-pattern-detection.

*3 = Opher Etzion, EPTS chair, has commented on this book from a CEP perspective.

This week OMG’s Technical Meeting has had most buzz around the BPMN 2.0 submission (and congratulations to that team, for which TIBCO is a supporter). Some of the other stuff going on includes:

• PRR or Production Rules Representation (which, for complex event processing like in TIBCO BusinessEvents, can include event-condition-action rules using standard forward-chaining semantics) starts the Revision Task Force process for PRR1.1. A few tweaks are due, but more interesting was to see 2 more vendors attend the PRR session this week. Also, note that UML tool NoMagic is presenting on PRR at ORF’09 later in the year…
• DMN or Decision Model and Notation started on its first stage of development, which is the identification of use cases and roles for defining UML-based decisions for a future RFP. We had some good discussions (which I’ll report in a future post once I have reported to the DMN community), and it is clear that this could be a very key standard for business modelers, end-users and tool vendors. Of course the relevance of this to event processing is that many CEP/EP systems’ role is to support decisions…

A somewhat hotter debate continues (/is) regarding the proposed Case Management RFP, which was developed from a Dynamic Business Activity Modeling RFI last year (which TIBCO responded to, and was also covered by our session at the recent Semantic BPM day in Berlin). Many BPM applications are also case management applications, but some case management requires more sophisticated event-handling, rule-driven processes, decision management, and case record management and recording (technologies that TIBCO mostly covers under BPM+). One school of thought is that the more sophisticated requirements for case management need to be rolled into the common BPM standards stack (including BPMN); another is that multiple different standards should be used flor flexibility (such as combining BPMN with BMM, PRR and DMN). From an event processing perspective, of course, case management (by one definition at least!) involves applying incoming events to the state of some case in order to determine whether processes need to be started, continued, halted or changed - in other words CEP technology can often be applied for case management areas in government, finance, healthcare, etc.

Some of the other case management discussions can be found from EBizQ, Bruce Silver, and Derek Miers.