規(guī)則引擎

1、Rule Engine-based Programming,Joinwork研發(fā)小組整理2004/11,內(nèi)容,面臨的問(wèn)題相關(guān)概念解決方案公司和產(chǎn)品,管理者的要求,為提高效率，管理流程必須自動(dòng)化，即使現(xiàn)代商業(yè)規(guī)則異常復(fù)雜市場(chǎng)要求業(yè)務(wù)規(guī)則經(jīng)常變化，IT系統(tǒng)必須依據(jù)業(yè)務(wù)規(guī)則的變化快速、低成本的更新為了快速、低成本的更新，業(yè)務(wù)人員應(yīng)能直接管理IT系統(tǒng)中的規(guī)則，不需要程序開發(fā)人員參與,管理者叫來(lái)程序員，希望程序員滿足他的要求,程序員

2、的苦惱,程序=算法+數(shù)據(jù)結(jié)構(gòu)有些復(fù)雜的商業(yè)規(guī)則很難推導(dǎo)出算法和抽象出數(shù)據(jù)模型軟件工程要求從需求->設(shè)計(jì)->編碼可業(yè)務(wù)規(guī)則常常在需求階段可能還沒(méi)有明確，在設(shè)計(jì)和編碼后還在變化業(yè)務(wù)規(guī)則嵌在系統(tǒng)各處代碼中 對(duì)程序員來(lái)說(shuō)，系統(tǒng)已經(jīng)維護(hù)、更新困難，更不可能讓業(yè)務(wù)人員來(lái)管理,程序員幾乎暈倒，還好他遇見了科學(xué)家，科學(xué)家介紹了自己的研究成果…,科學(xué)家的成果,人工智能（AI）,機(jī)器人,視覺,語(yǔ)音,人工神經(jīng)系統(tǒng),自然語(yǔ)言,

3、專家系統(tǒng),推理方法領(lǐng)域知識(shí)知識(shí)的表示獨(dú)立于知識(shí)的外殼（shell）,基于規(guī)則的專家系統(tǒng)組成,知識(shí)庫(kù),規(guī)則：知識(shí)的表示，模擬人類問(wèn)題求解的產(chǎn)生式規(guī)則交通法規(guī)知識(shí)的規(guī)則表示“紅燈”規(guī)則： IF 亮紅燈 THEN 停下來(lái)“綠燈”規(guī)則： IF 亮綠燈 THEN 走前件( A n t e c e d e n t )、條件部分(Conditional part)、模式部分(Pattern part)或左部(Left-han

4、d-side, LHS)，單獨(dú)的條件“亮綠燈”稱為條件元素(Conditional element)或一個(gè)模式( P a t t e r n )。后件( C o n s e q u e n t )或右部(Right-hand side, RHS)：是規(guī)則觸發(fā)時(shí)將要執(zhí)行的一系列行為( A c t i o n )。,工作內(nèi)存( Working memory),被規(guī)則所使用的事實(shí)的全局?jǐn)?shù)據(jù)庫(kù)包含關(guān)于交通燈當(dāng)前狀態(tài)的事實(shí)如“亮綠燈”或“亮

5、紅燈”，這些事實(shí)可能一個(gè)或者兩個(gè)同時(shí)在工作記憶中。,推理機(jī)(Inference engine),通過(guò)決定哪些規(guī)則滿足事實(shí)或目標(biāo)，并授予規(guī)則優(yōu)先級(jí)，滿足事實(shí)或目標(biāo)的規(guī)則被加入議程。正向鏈 (Forward chaining)和反向鏈(Backward chaining)正向鏈?zhǔn)菑氖聦?shí)到結(jié)論的推理反向鏈則是從假設(shè)，即要證明的結(jié)論，到事實(shí)的推理。,議程( A g e n d a ),由推理機(jī)創(chuàng)建的一個(gè)規(guī)則優(yōu)先級(jí)表，這些規(guī)則匹配工作內(nèi)存中

6、的事實(shí)同時(shí)會(huì)有多個(gè)規(guī)則和事實(shí)匹配，優(yōu)先級(jí)最高的被觸發(fā)被觸發(fā)規(guī)則的動(dòng)作可能會(huì)產(chǎn)生新的事實(shí)，新的事實(shí)被加入工作內(nèi)存,知識(shí)獲取機(jī)(Knowledge acquisition facility),為用戶建立的一個(gè)知識(shí)自動(dòng)輸入方法，以代替知識(shí)工程師去編碼知識(shí)。,解釋機(jī)(Explanation facility),解釋系統(tǒng)的推理給用戶專家系統(tǒng)的輸出,專家系統(tǒng)與傳統(tǒng)程序的差別,耐心聽到此處，程序員忽有所悟…,進(jìn)行以下快速模式匹配 業(yè)務(wù)規(guī)

7、則嵌在各處代碼中…控制與數(shù)據(jù) \ 隱含在一起 ? 明確分開 ! 很難推導(dǎo)出算法 ..? 由……求解 \ 算法 ?? 規(guī)則和推理機(jī) ..修改 \ 難 ? 較易 !! 業(yè)務(wù)規(guī)則….變化!! 擴(kuò)充 \ 很大改動(dòng) ! 逐步增加…..,程序員的大腦,程序員大腦當(dāng)然比專家系統(tǒng)速度快，以下是其計(jì)算結(jié)果,業(yè)務(wù)規(guī)則引擎架構(gòu),Rules authoring environment,Decision Table,Ruleflow,Rule Engine AP

8、Is,JSR 94 APIs for basic rule engine operations, such as rules for parsing, adding facts to the working memory, and firing rulesExpert Group:Art Technology Group Inc.(ATG)、 BEA Systems、Fujitsu Limited 、 IBM、ILOG 、

9、 Novell, Inc. 、Oracle 、UnisysStatusProposed Final Draft 29 Oct, 2003 Public Review 11 Sep, 2002Community Draft Ballot 19 Feb, 2002Community Review 19 Feb, 2002Expert Group Formation 19 Dec, 2000

10、JSR Review Ballot 27 Nov, 2000,Rules repository (XML),KQML (Knowledge Query and Manipulation Language) : http://ksl.stanford.edu/knowledge-sharing RuleML(Rule Markup Language) :http://www.dfki.uni-kl.de/rulem

11、l BRML : IBM CommonRules http://alphaworks.ibm.com/Business Rule Exchange - the Next XML Wave ?to exchange knowledge via XML, not just data.,Discount ：If the total purchase amount of a shopping cart is > 100

12、$ Then Set the discount for the shopping cart to 0.1% RuleML：,RuleML Example,Rule Engine Core,優(yōu)化的RETE 算法正向鏈 (Forward chaining)DEMO,Implement business ru

13、le engines in a J2EE enterprise,J2EE rule engine architecture,程序員的杰作,Empower business users to change and maintain their own production systems without programming help and without interrupting operations Build and inte

14、grate sophisticated object models incorporating corporate data sources including databases and XML schemas Use drag and drop visual layout tools to design complex rule-driven process flows with conditional branching, re

15、usable rulesets, functions, and question sets Personalize business processes and portals with user-specific data displays, interactive dialogs, and product recommendations Deploy highly scalable rule systems with excep

16、tional performance on all leading platforms,干完活，程序員去見管理者，得意的說(shuō)：“… …”,公司(個(gè)人)和產(chǎn)品,Fair, Isaac : Blaze Advisor v4.5 used by WebSphere Commerce ILOG, Inc. : JRules v4.5 , Rulesused by ChordiantYasu Technologies : Qu

17、ickRules v2.6有免費(fèi)30天試用版下載Ernest J. Friedman-Hill : Jess 6.1 … …,市場(chǎng)人員的說(shuō)法,“ Business rule engines are moving toward maturity. In 2003, they will support business agility when called on to do so ”The Business R

18、ule Engine 2003 Magic Quadrant. 7 April 2003 , Gartner“A Gartner survey showed a return on investment of nearly 10 percent in IT costs being saved by using business rule technology. The future savings

19、 and benefits of business rule engines are expected to grow significantly over time.”Rules: Adding Intelligence to the Enterprise Architecture. 18 July 2002 , Gartner,參考材料,1. Business process automa

20、tion made easy with Java Part 1 & 2 By Ahmed Abulsorour and Siva Visveswaran September 6, 2002 2. Implementing a Rule-Driven Service Oriented Architecture By Daniel C. Hayes

21、 July 20033. Expert Systems Principles and Programming（專家系統(tǒng)原理與編程）By Joesph Giarratano4. Business Rule Exchange - the Next XML Wave By Margaret Thorpe 5. http://www.jcp.org/en/jsr/detail?id=0946. htt