“ Managing Business Logic with rule based technologies” Michael Neale OSDC – Sydney - 2008

Michael Neale

OSDC – Sydney - 2008

And a little about me: “ first Australian JBoss Employee” Was lonely for a while (but now we are part of Red Hat family !).

And a little about me:

“ first Australian JBoss Employee”

Was lonely for a while (but now we are part of Red Hat family !).

Rules/Expert Systems Were once delivered as expert system shells Extract logic “out of code” Explicit rules “On the fly” changes to rules

Were once delivered as expert system shells

Extract logic “out of code”

Explicit rules

“On the fly” changes to rules

History 1970's – MYCIN Production Rules Generalised into a “shell” that can be re-used 90's - “business rule engines”

1970's – MYCIN

Production Rules

Generalised into a “shell” that can be re-used

90's - “business rule engines”

Production Rules if/when <condition> then <action> Logic programming Logical chaining (you may remember prolog)

if/when <condition> then <action>

Logic programming

Logical chaining

(you may remember prolog)

Why bother? “Greenspunning” Have been in use for some time Being declarative is (often) good for you

“Greenspunning”

Have been in use for some time

Being declarative is (often) good for you

When to use Domain expertise available Dynamic changes to rules separate from SDLC One point of truth for “the business rule”

Domain expertise available

Dynamic changes to rules separate from SDLC

One point of truth for “the business rule”

Pattern Matching Pattern matching is central ... but a quality “model” is needed results in looser coupling ... which means longer term change tolerance

Pattern matching is central

... but a quality “model” is needed

results in looser coupling

... which means longer term change tolerance

Engines ... inference or scripting engine?

... inference or scripting engine?

Scripting approach Simple, easy

Simple, easy

Higher order logic Higher order logic Dealing with knowledge bases with lots of “static” data RETE algorithm (an optimisation)

Higher order logic

Dealing with knowledge bases with lots of “static” data

RETE algorithm (an optimisation)

Rete

Rules “ Agenda” Rules finding facts or facts finding rules? Changed facts Stable facts

Example applications Underwriting, pricing insurance Real time traffic monitoring and recommendation Mortgage pricing Claim (insurance) process legal compliance VISA, Mastercard fraud detection Logistics routing

Underwriting, pricing insurance

Real time traffic monitoring and recommendation

Mortgage pricing

Claim (insurance) process legal compliance

VISA, Mastercard fraud detection

Logistics routing

User interface “visual metaphors”

“visual metaphors”

A dose of reality Over-promising in the 90's Underdelivering “who needs a programmer”

Over-promising in the 90's

Underdelivering

“who needs a programmer”

CLIPS Thanks NASA ! (defrule engine-sluggish &quot;&quot; (engine-sluggish yes) (not (repair ?)) => (assert (repair &quot;Clean the fuel line.&quot;))) (defrule engine-misfires &quot;&quot; (engine-misfires yes) (not (repair ?)) => (assert (repair &quot;Point gap adjustment.&quot;)))

Thanks NASA !

(defrule engine-sluggish &quot;&quot;

(engine-sluggish yes)

(not (repair ?))

=>

(assert (repair &quot;Clean the fuel line.&quot;)))

(defrule engine-misfires &quot;&quot;

(engine-misfires yes)

(not (repair ?))

=>

(assert (repair &quot;Point gap adjustment.&quot;)))

Clips integration Shell or command line style Detailed C API and sample code clips.h Embed it in your native apps

Shell or command line style

Detailed C API and sample code

clips.h

Embed it in your native apps

Drools Targets JVM (also a .Net port) at present Originated from codehaus community (now jboss) Has developer + analyst tools

Targets JVM (also a .Net port) at present

Originated from codehaus community (now jboss)

Has developer + analyst tools

Drools example rule engine-sluggish when Engine(sluggish = true) not Repair() then insert(new Repair(“clean fuel line”)) end rule engine-misfires: when Engine(misfires=true) not Repair() then insert(new Repair(“Point gap adjustment”)) end

rule engine-sluggish

when

Engine(sluggish = true)

not Repair()

then

insert(new Repair(“clean fuel line”))

end

rule engine-misfires:

when

Engine(misfires=true)

not Repair()

then

insert(new Repair(“Point gap adjustment”))

end

Thanks... Questions? michaelneale.blogspot.com twitter.com/michaelneale http://friendfeed.com/rooms/osdc

Questions?

michaelneale.blogspot.com

twitter.com/michaelneale

http://friendfeed.com/rooms/osdc