Service-Oriented Computing: Semantics, Processes, Agents August 2004 Chapter 17: Organizations Service-Oriented Computing: Semantics, Processes, Agents – Munindar P. Singh and Michael N. Huhns, Wiley, 2005 © Singh & Huhns

Highlights of this Chapter Service-Oriented Computing: Semantics, Processes, Agents August 2004 Highlights of this Chapter Contracts Spheres of Commitment Policies Negotiation  Omitted Chapter 17 Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns © Singh & Huhns

Why Organizations? Computational representation inspired by human organizations Map to business partners providing or using services Promote coherence in interactions Offer a conceptually natural, high-level basis for understanding and designing service interactions Chapter 17 Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns

Organizations Organizations nest, though usually not as trees All organizations are agents Some agents are organizations Organizations help overcome limitations of individuals in Reasoning Capabilities Perception Lifetime, persistence Chapter 17 Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns

Three Kinds of Organizations Concrete (instantiated): agents playing roles Configured, run-time concept Abstract (templates): roles and relationships among roles Design-time concept Institutions: part abstract and part concrete Run-time concept, but the membership can change Example: eBay Buyers and sellers can change But eBay itself is a fixed participant Chapter 17 Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns

Legal Abstractions Contracts Directed obligations Hohfeldian concepts Compliance Chapter 17 Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns

Contracts as Service Agreements Contracts structure interactions (i.e., service engagements) among autonomous parties People and corporations Governmental agencies Compare with contracts in programming Each needs a computational representation Key questions: how to create, modify, perform, or monitor contracts Chapter 17 Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns

Motivation for Contracts Provide a basis for service agreements Crucial in open environments Emphasize public behavior: observable by others Constrain behavior: limit autonomy Mostly disregard internal implementations, thus supporting heterogeneity May expose some implementation Chapter 17 Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns

Legal Concepts Inherently multiagent: about interactions among autonomous parties Directed obligations One party being obliged to another party Multiagent flavor Contrast with traditional deontic logic Zero-agent: it is obligatory that … One-agent: you are obliged to do … Chapter 17 Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns

Rights The rights or claims a party has on another party Not the right (ethical) thing to do The claims of one party are the duties of another: claim is a correlate of duty Chapter 17 Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns

Hohfeldian Concepts: 1 The term right is used ambiguously Sixteen concepts distinguish the main situations: Four main concepts Their correlates Their negations Their negations’ correlates Chapter 17 Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns

Hohfeldian Concepts: 2 Claim-duty: as above Privilege-exposure: freedom from the claims of another agent Power-liability: when an agent can change the claim-duty relationship of another agent Immunity-disability: freedom from the power of another agent Chapter 17 Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns

Service-Oriented Computing: Semantics, Processes, Agents August 2004 Commitments A commitment Involves three parties: a debtor commits to a creditor within an organizational context Is scoped by its (organizational) context May be manipulated, subject to additional commitments Is public (unlike beliefs) Commitments provide Flexible interactions, thus promoting coherence A basis for judging compliance Chapter 17 Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns © Singh & Huhns

Manipulating Commitments Service-Oriented Computing: Semantics, Processes, Agents August 2004 Manipulating Commitments Operations on commitments: Create Discharge (satisfy) Cancel Release (eliminate) Delegate (change debtor) Assign (change creditor) Metacommitments constrain the manipulation of commitments Chapter 17 Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns © Singh & Huhns

Commitments for Contracts A contract is a set of related commitments Provides a notional context to the commitments Applies between specified parties, in a context (e.g., UCC, real-estate, Internet commerce) In contrast to commitments, other approaches: Single-agent focused, e.g., deontic logic Don’t handle organizational aspects of contracts Don’t accommodate manipulation of contracts Chapter 17 Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns

SoCom: Sphere of Commitment A computational abstraction based on organizations An institution with additional features Involves roles (abstract) or agents (concrete) A witness for the commitment Trusted party to decide satisfaction or violation A locus for testing compliance and enforcing corrections (e.g., compensation) Chapter 17 Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns

Service-Oriented Computing: Semantics, Processes, Agents August 2004 SoComs and Structure A SoCom inherits policies from surrounding (contextual) SoCom E.g., UCC applies to commercial interactions Inherited policies can conflict because of Nonunique nesting When agents play multiple roles - Munindar Singh and Michael Huhns © Singh & Huhns

Virtual Enterprises (VE) A VE offers commitments beyond those of its members to support business atomicity Sellers come together with a new proxy agent called VE Example of VE agent commitments: Entertain order updates Notify on change of order Price guarantee Delivery date guarantee Chapter 17 Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns

A Selling VE (Composition Example) Chapter 17 Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns

Teams Tightly knit organizations Goals shared by all team members Commitments to help team members Commitments to adopt additional roles and offer capabilities on behalf of a disabled member Chapter 17 Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns

Teamwork When a team carries out some complex activity Negotiating what to do Monitoring actions jointly Supporting each other Repairing plans Chapter 17 Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns

Service-Oriented Computing: Semantics, Processes, Agents August 2004 Chapter 17 Summary Organizations are a natural metaphor for understanding and designing systems of services Organizations provide a basis for realizing coherent interactions Legal and contractual concepts such as commitments Teamwork Understanding and formalizing negotiation Chapter 17 Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns © Singh & Huhns