EOMAS 2015 – 11TH INTERNATIONAL WORKSHOP ON ENTERPRISE & ORGANIZATIONAL MODELING AND SIMULATION

STOCKHOLM, SWEDEN 8-9 OFJUNE 2015

VIRTUAL ENTERPRISE SYNTHESIS BY WEB SERVICES COMPOSITION WITH HTN-LIKE PARSING ALGORITHM

ROMANOV, VICTOR - DOCTOR OF TECHNICAL SCIENCES, PROFESSOR OF THE DEPARTMENT FOR INFORMATION SYSTEMS IN ECONOMICS AND MANAGEMENT OF THE PLEKHANOV RUSSIAN UNIVERSITY 

EFIMOVA, SVETLANA - STUDENT

YUDAKOVA, KATERINA - STUDENT

VARFOLOMEEVA, ALEKSANDRA - ASSISTANT OF THE DEPARTMENT FOR IINFORMATICS

VIRTUAL ENTERPRISE AS A TREND

•THERE IS A CLEAR TREND THAT THE MODERN MANUFACTURING PROCESS DOES NOT TO BE CARRIED ON BY A SINGLE ENTERPRISE ANY MORE, RATHER EVERY ENTERPRISE IS JUST ONE NODE THAT ADDS SOME VALUE (A STEP IN THE MANUFACTURING CHAIN) TO THE ENTIRE PRODUCTION CYCLE.

•A VIRTUAL ENTERPRISE IS A TEMPORARY ALLIANCE OF COOPERATING ENTERPRISES THAT ACTS AS A SINGLE ORGANIZATION TO SHARE SKILLS, CORE COMPETENCIES AND RESOURCES IN ORDER TO REACT QUICKLY TO CHANGES IN THE MARKET CONDITIONS AND BECOME AGILE ENTERPRISES. THIS COLLABORATION IS CARRIED OUT USING COMPUTER NETWORKS.

WEB-SERVICES

A COMPLETE WEB SERVICE IS ANY SERVICE THAT:

•IS AVAILABLE OVER THE INTERNET OR PRIVATE (INTRANET) NETWORKS.

•USES A STANDARDIZED XML MESSAGING SYSTEM.

•IS NOT TIED TO ANY ONE OPERATING SYSTEM OR PROGRAMMING LANGUAGE.

•IS SELF-DESCRIBING VIA A COMMON XML GRAMMAR.

•IS DISCOVERABLE VIA A SIMPLE FIND MECHANISM.

Elaboration of architecture of

developed system

Architecture requirements translation

on formal language

Set of queries developing for

web-service search

Requesting UDDI

Getting web-services

description

Web-services composition according to

their semantic description

Elaboration of web-service

HTN SOAP WСF

WSDL, OWL-SDomain ontology

Arcitecture design

principles

User Developer

STAGES OF INFORMATION SYSTEM DEVELOPMENT

•STAGE 1: USER ELABORATES REQUIREMENTS TO THE DEVELOPED SYSTEM AND ITS ARCHITECTURE.

•STAGE 2: TO TRANSLATE THE RECEIVED REQUIREMENTS OF THE FORMAL LANGUAGE. ONTOLOGIES ARE USED FOR THIS PURPOSE. A STANDARD ONTOLOGY CONSISTS OF A SET OF BASIC CLASSES AND PROPERTIES. IT IS USED TO DECLARE AND DESCRIBE SERVICES.

•STAGE 3: THE SET OF REQUESTS FOR SEARCH OF A WEB SERVICE IS WORKED OUT. SEVERAL TECHNOLOGIES, SUCH AS SOAP, WSDL, ARE BEING DEVELOPED TO PROVIDE A STANDARD WAY OF DESCRIBING WEB SERVICES.

•STAGE 4-5: PUBLISHING THE DESCRIPTION OF THE SERVICE IN THE GLOBAL REGISTRY BY THE DEVELOPER AND SEARCHING FOR IT BY A CLIENT WITH THE HELP OF UDDI.

•STAGE 6: COMPOSITION OF VE FROM OBTAINED WEB-SERVICES.

WEB-SERVICE COMPOSIION

THE COMPOSITION AS AUTOMATED PLANNING

The most of composition algorithms are based on the automated planning algorithms.

The problem of automated planning is not new, research in this domain are continuing for more than 50 years (STRIPS, HTN algorithms, automated planning languages ADL, PDDL).

The languages of planning are based on the situation calculus, that is some extension of the first order predicate calculus

LET L- BE FIRST ORDER PREDICATE LANGUAGEВ, f– SENTENCE (FORMULA) AT L. WE WILL DENOTE THE SET OF SENTENCES BY F. LET THESE SENTENCE ARE DESCRIBING THE STATES OF SOME OBJECT. SO STATE s IS A SET OF SENTENCES sS.

LET WE HAVE INITIAL STATE OF THE OBJECT S0 AND GOAL STATE SG . THEN WE HAVE SOME SET OF ACTIONS A. THE ACTION HAS A NAME a AND PARAMETERS a(ξ), AND ALSO PRECONDITION pre(a), POSITIVE POSTCONDITION add(a) AND NEGATIVE POSTCONDITION del(a).

POSTCONDITION DEFINES THE RESULT OF ACTION EXECUTION THAT IS DESCRIBES SITUATION CHANGE. POSITIVE POSTCONDITION ADDS TO THE SITUATION DESCRIPTION NEW TRUE SENTENCE< THE NEGATIVE ONE- DELETE TRUE SENTENCE.

THERFORE THE ACTION IS A SET OF THE NEXT SET ELEMENTS: {a(ξ), pre(a), add(a), del(a)}. LET γ BE TRANSITION FUNCTION FROM STATE s TO THE STATE s’ AS RESULT OF ACTION a: s’=γ(s,a). THEN FORMAL DEFINITION OF THE PLANNING TASK IS; FINDA SEQUENCE OF ACTONS AND STATES, SUCH AS: s1=γ(s0, a1), s2= γ(s1, a2)…sn= γ(sn-1, an) AND sn=sg.

THE STATEMENT OF THE PLANNING TASK

VALUES ASSIGNMENT TO PARAMETERS O THE ACTIONS

Web-description of the service WSDi is translated to the definition of the operator Аi, on the base of the web-

services OWL--S profilename (Ai ) = WSDiID.

pre(Ai) }}{}{11

n

kki

n

kki itionhasPrecondWSDhasInputWSD

add(Ai) }}{}{ 11

n

kki

n

kki hasEffectWSDhasOutputWSD

del(Ai) }}{1

n

kki hasEffectWSD

STRIPS AND HTN ALGORITHMSSTRIPS(A, s, g) *p = empty planloop…if s satisfies g then return pa = [an applicable action in A, relevant for g]if a = null, then return failurep’ = STRIPS(A, s, precond(a))if p’ = failure, then return failures = apply p’ to ss = apply a to sp = p + p’ + a

The HTN-algorithm differs from classical in that here besides from elementary operators are created operators groups, named as tasks and by such way hierarchical network of tasks is formed. This approach remind us formal grammars and compilers theory with its terminal and non terminal string and possibility of decreasing search process by excluding considering combination of symbols belonging to the diferent categories. *http://www.sharprobotica.com/2011/04/strips-for-classical-plan-representation-and-

planning/STRIPS for Classical Plan Representation and Planning

PARSING TREE OF VIRTUAL ENTERPRISE ON THE EXAMPLE OF TRAVEL AGENCY

TERMINAL AND NONTERMINAL SYMBOLS OF THE TRAVEL AGENCY FORMAL GRAMMAR

THE ATOMIC SERVICES (TERMINAL SYMBOLS) :

• lt” IS FOR LOCAL TAXI •“lpt” IS FOR LOCAL PUBLIC TRANSPORT•“dt” IS FOR DESTINATION TAXI•“dpt” IS FOR DESTINATION PUBLIC TRANSPORT •“pc” IS FOR PASSPORT CONTROL•“b” IS FOR BOARDING •“le” IS FOR LUGGAGE EXAMINATION •“sh” IS FOR SHOPPING •“ex” IS FOR EXCURSIONS•“su” IS FOR SURFING•“sb” IS FOR SUNBATHING;•“y” IS FOR “YOGA •“d” IS FOR DIVING •“ws” IS FOR WATER SKIS•“cI” IS FOR CHECK-IN •“r” IS FOR RESTAURANT• “bih” IS FOR BREAKFAST IN THE HOTEL.

THE COMPOSITE SERVICES (NONTERMINAL SYMBOLS) :

• “S” is for tour package composite services;

• “TR” is for transportation composite services;

• “TA” is for transportation to the airport composite services;

• “TH” is for transportation to the hotel composite services;

• “FL” is for flight composite services;

• “ST” is for stay composite services;

• “F” is for food composite services;

• “AC” is for accommodation composite services;

• “ACT” is for activity composite services;

• “RE” is for relaxation;• “SP” sport composite services;

FOR TRANSPORTATION ATOMIC AND COMPOSITE SERVICES;“TA” IS FOR TRANSPORTATION TO THE AIRPORT COMPOSITE SERVICES;“TH” IS FOR TRANSPORTATION TO THE HOTEL COMPOSITE SERVICES;“FL” IS FOR FLIGHT COMPOSITE SERVICES;“It” IS FOR LOCAL TAXI ATOMIC SERVICE;“lpt” IS FOR LOCAL PUBLIC TRANSPORT ATOMIC SERVICE;“dt” IS FOR DESTINATION TAXI ATOMIC SERVICE;“dpt” IS FOR DESTINATION PUBLIC TRANSPORT ATOMIC SERVICE;“pc” IS FOR PASSPORT CONTROL ATOMIC SERVICE;“b” IS FOR BOARDING ATOMIC SERVICE;“le” IS FOR LUGGAGE EXAMINATION ATOMIC SERVICE;

THE RULES OF THE FORMAL GRAMMAR

S → TR & STTR → TA & TH & FL

TA → lt lptTH → dt dpt

FL → pc & b & leST → ACT & AC & F

F → r bihAC → ci

ACT → sh ex SPSP → su d ws

The symbols are used in the following meanings:→ substitution (inference) rule& – all symbols belong to concatenation. – only one symbol belongs concatenation.

–including of one or more symbols of the previous level.

HTN-LIKE ALGORITHM OF COMPOSITION OF WEB-SERVICES

1. TERMINAL SYMBOLS APPEAR ON THE INPUT TAPE.

2. TERMINAL SYMBOLS ARE READ BY THE STACK AUTOMATON AND PLACED IN THE STACK FOR SUBSEQUENT ANALYSIS AND RECOGNITION.

3. THE STRING OF TERMINAL SYMBOLS BEGINS AND ENDS WITH THE SYMBOL “#”.

4. THE STACK IS CONNECTED WITH RECOGNIZERS OF TERMINAL SYMBOLS AND RECOGNIZERS OF NONTERMINAL SYMBOLS.

5. THE RECOGNIZERS OF TERMINAL SYMBOLS ASSOCIATE EVERY TERMINAL SYMBOL WITH ONE OF THE FINITE NUMBER OF THE CATEGORIES OF NONTERMINAL SYMBOLS.

6. EVERY RECOGNIZER OF TERMINAL SYMBOLS HAS MEMORY IN THE FORM OF THE LIST OF TERMINAL SYMBOLS THAT BELONG TO THE CERTAIN CATEGORY. EVERY RECOGNIZER COMPARES A TERMINAL SYMBOL IN THE STACK WITH EVERY TERMINAL SYMBOL STORED IN ITS LIST.

B1 → A1&A2&A3

B2 → A4

HTN-LIKE ALGORITHM OF COMPOSITION OF WEB-SERVICES

6. THE DEFINED CATEGORIES THAT INCLUDE EXISTING TERMINAL SYMBOLS ARE PLACED IN THE STACK.

7. WHEN EVERY TERMINAL SYMBOL IS ASSOCIATED WITH ONE OF THE CATEGORIES, THE STRING OF NON TERMINAL SYMBOLS IS CONSIDERED TO BE FORMED.

THE STRING OF NON TERMINAL SYMBOLS ALSO BEGINS AND ENDS WITH THE SYMBOL “#”.

THE ANALYSIS OF THE STRING OF NON TERMINAL SYMBOLS BEGINS.8. THE RECOGNIZERS OF NON TERMINAL SYMBOLS OPERATE ON THE RECEIVED NON TERMINAL SYMBOLS.

 EVERY NONTERMINAL SYMBOL HAS A COUNTER DENOTING ITS VALENCE (N) – THE NUMBER OF INFERIOR SYMBOLS (E. G. VALENCE OF S =2). WHEN THE COUNTER IS RESET TO ZERO, THE STRING OF THE NON TERMINAL SYMBOLS OF THE NEXT LEVEL BEGINS TO FORM.

THE ALGORITHM ENDS WHEN THE UPPER-LEVEL SYMBOL S IS DEFINED.

S → B1&B2

HOW THE BOTTOM-UP RECOGNIZER ACCEPTS

THE INPUT STRING WHILE PARSING THE INPUT STRING

(; it lpt dpt pc b le)(it; lpt dpt pc b le) SHIFT(TA lpt; dpt pc b le) REDUCE, 2(TA; dpt pc b le) ABSORPTION,2(TA dpt ; pc b le) SHIFT(TA TH ; pc b le) REDUCE, 3(TA TH pc  ; b le) SHIFT (TA TH pc  b; le) SHIFT(TA TH pc  b le;) SHIFT(TA TH FL;) REDUCE, 4(TR) REDUCE,1 •  •  •  

RELEVANT RULES

1. TR → TA & TH & FL

2. TA → lt lpt

3. TH → dt dpt

4. FL → pc & b & le

THANK YOU FOR ATTENTION,

QUESTIONS, PLEASE.