OWL-P: Processes = Protocols + Policies Munindar P. Singh ( Students: Amit K. Chopra, Nirmit V. Desai, Ashok U. Mallya) singh@ncsu.edu Department of Computer Science North Carolina State University http://www.csc.ncsu.edu/faculty/mpsingh/ � Singh et al. , November 2004 – p.1/29 c
Problem, Solution, Approach Problem: Modeling and enacting open business processes Traditional approaches can’t handle autonomy, heterogeneity, dynamism Incorporating context is essential Solution: Interaction is the key New way of thinking geared toward open systems Approach: Protocols capture interaction Software engineering: refine, aggregate protocols Agents: flexible enactment � Singh et al. , November 2004 – p.2/29 c Compliance in the face of flexibility
Accomplishments: Intellectual Protocols provide interaction-centric modeling, leaving policies to participants Commitment semantics yield flexible modeling and enactment Theory of protocols supports reusability, refinement, and aggregation of interactions Students Three PhD dissertations being supported PhD dissertation involving autonomic service selection based on OWL for QoS being defended on Dec 6. � Singh et al. , November 2004 – p.3/29 c
Accomplishments: Implementational On SemWebCentral OWL-P as an OWL ontology (using SWRL) Roles Messages: content as propositions and commitments Rules to describe messages and roles Protégé plugin for OWL-P protocol editor Protocol composer and skeleton generator Agent-based architecture layered on FIPA Rule-based policies that help agents satisfy their protocol roles � Singh et al. , November 2004 – p.4/29 c
Accomplishments: Evangelical Papers, tutorials, panels, invited talks Trying to reach the software engineering community: well-received at OOPSLA Contact with IBM and HP Beginning project jointly with IBM on autonomic and agent based business process management New book: Service-Oriented Computing: Semantics, Processes, Agents IEEE Internet Computing track (2005) on Service-Oriented Computing � Singh et al. , November 2004 – p.5/29 c
The Essential Tension Reusability requires Context freedom Encapsulation Usability (usefulness) requires Context sensitivity Varieties of context include organizations, laws, and the real world Main idea Autonomy: components have a life of their own Interactions are what matter � Singh et al. , November 2004 – p.6/29 c
A Process is . . . Orchestration: a partial order of actions under the control of a central conductor Akin to a workflow or flow in BPEL Choreography: an exchange of messages among participants Akin to a conversation as described by WS-Chor Collaboration: a joint set of activities among business partners Akin to real business; essential for SOAs � Singh et al. , November 2004 – p.7/29 c
Emphases of Collaboration t n Dynamic e e c n Organizations m n t o i c a t i l a a p n Rule-Based d i e l m Commitment a o d v c n Protocols: Flexibility a d d n n n a a o i Commitment Protocols: t g g a n n t i i l Content & Compliance r n e o e t d i m o n e o l M p Protocols: Modularity M m I � Singh et al. , November 2004 – p.8/29 c
Innovations: 1 Protocols: Conceptually decentralized, reusable, encapsulations of processes Commitments: Content for protocols Support reuse via abstractions for refinement and aggregation of protocols What the protocol should accomplish What deviations are legitimate and what aren’t Operational semantics for commitments � Singh et al. , November 2004 – p.9/29 c
Innovations: 2 Rule-Based Reasoning: Expressing protocols flexibly Accommodating context Deciding specific actions by applying policies Spheres of Commitment: Modeling organizations Enacting protocols Monitoring and verifying compliance Slogan: Processes = Protocols + Policies � Singh et al. , November 2004 – p.10/29 c
Trends and Assessment Increasing # of business protocols IOTP , Escrow, SET, NetBill, . . . RosettaNet: 107 Partner Interface Processes (PIPs) ebXML Business Process Specification Schema (BPSS) Intended to be legally binding Generally highly limited: two party, request-response protocols No commitments; no formal semantics Limited support for modeling or enactment � Singh et al. , November 2004 – p.11/29 c
Vision Target Audience: Practitioners Formalization in the background Engineering: not full automation, but tools for Modeling and validation of protocols Modeling and validation of processes Generation of software components Enactment via Spheres of Commitment Monitoring and compliance � Singh et al. , November 2004 – p.12/29 c
Usage Scenario Software Designer MERCHANT 3 Composer Merchant Local specify + Skeleton Axioms Policy OWL-P 2 Purchase OWL-P 6 Merchant Order Shipping Payment Local OWL-P OWL-P OWL-P Process 4 1 register Protocol 5 7 Repository lookup register 10 Customer C Policy + Local Purchase.Customer Skeleton U Skeleton S OWL-P T 9 Merchant Port O 11 UDDI M E Repository Customer Local R Search Merchant Process 8 � Singh et al. , November 2004 – p.13/29 c
Simple Scenario and Example Run A customer (C) looks up a book at a vendor (B) and is quoted price and availability C orders the book from B B ships to C C pays B s 0 reqQuote(c,b,g) s 1 sendQuote(b,c,g,p) s 2 sendAccept(c,b,p) s 3 sendGoods(b,c,g) s 4 sendMoney(c,b,p) s 5 Customer, c Bookstore, b � Singh et al. , November 2004 – p.14/29 c
Process View: Flow or Protocol Pay Bank Bookstore Send Select Customer Receipt Bookstore Customer Ship Customer Bookstore Customer Shipper Bookstore Bookstore Ship Select Order Shipper Pay Ship Customer Pay Bank � Singh et al. , November 2004 – p.15/29 c
Challenges: Modeling Refinement: pay by credit card versus pay Extensibility: verify C’s attributes, e.g., age Adjustment: receive payment before shipping; receive book before paying Alternative execution examples: B arranges for a shipper (S) to deliver the book to C C pays via bank (K) Compose a process from the above � Singh et al. , November 2004 – p.16/29 c
Refinement of Protocols Selection criteria for protocols Functional: pay versus ship Nonfunctional: payer trusts payee or not Pay Pay Pay with Pay Pay Pay cash receipt with via via debit check credit card card Pay with cash and receipt � Singh et al. , November 2004 – p.17/29 c
Aggregation of Protocols A simplified protocol may be revealed to a give role Decisions could be taken internally but not exposed Bookstore Ship Select Order Shipper Pay Ship Customer Pay Bank � Singh et al. , November 2004 – p.18/29 c
Example Run: Pay via Bank s 0 s 1 reqQuote(c,b,g) s 2 sendQuote(b,c,g,p) sendAccept(c,b,p) s 3 s 21 s 4 sendGoods(b,c,g) authPay(c,b,p) sendMoney(k,b,p) s 5 Customer's Bookstore, b Customer, c Bank, k � Singh et al. , November 2004 – p.19/29 c
Example Run: Shipper Protocol reqQuote(m,s,[gv]) s 10 sendQuote(s,m,[gv],q) s 11 sendAccept(m,s,[gv],q) s 12 s 13 s 13 sendGoods(m,g,s) s 14 sendGoods(s,v,g) s 15 sendMoney(m,s,q) s 15 s 16 Receiver, v Sender, m Shipper, s � Singh et al. , November 2004 – p.20/29 c
Example Run: Composed Purchase reqQuote(c,b,g) s 0 sendQuote(b,c,g,p) s 1 sendAccept(c,b,g,p) s 2 Shipping reqQuote(b,x,[gc]) s 3 sendQuote(x,b,[gc], px) s 11 s 12 sendAccept(b,x,[gc],px) s 13 s 13 Payment sendGoods(b,g,x) s 14 authPay(x,p) sendGoods(x,c,g) s 4 sendMoney(b,x,px) sendMoney(k,x,p) s 21 s 5 s 16 Shipper, x Bank, k Customer, c Bookstore, b � Singh et al. , November 2004 – p.21/29 c
Challenges: Enactment Behaving adaptively: decide dynamically to ship before payment to trusted Cs Handling exceptions External problems: cannot ship book Context-sensitivity: not legal for kids Detecting violations: no payment; book arrives damaged Correcting violations: remind, complain, refund, . . . Exploiting opportunities: combine orders from same C � Singh et al. , November 2004 – p.22/29 c
Example Run: Return and Refund Example: Uniform Commercial Code (UCC) allows returns with refunds for goods that are received damaged reqQuote(c,b,g) s 0 s 1 sendQuote(b,c,g,p) s 2 acceptQuote(c,b,p) s 3 sendGoods(b,c,g) s 4 sendMoney(c,b,p) s 5 s 5 returnGoods(c,b,g) s 18 s 19 sendRefund(b,c,p) Customer, c Bookstore, b � Singh et al. , November 2004 – p.23/29 c
Processes = Protocols + Policies Operational patterns Time outs, remind, garbage collect, . . . Decisions to manipulate: delegate, assign, . . . Enact protocols dynamically based on agent policies and context Transactional patterns Induce transactional scopes Apply retry, redo, undo (compensate) where appropriate Enact via Spheres of Commitment � Singh et al. , November 2004 – p.24/29 c
Remaining Work: Easy Challenge Remediation Simplify protocol design Libraries of compos- for business able protocols Produce compliant Refined methodology agents based on policies Make up to date with Freshen the work Rules work and OWL-S � Singh et al. , November 2004 – p.25/29 c
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