The Value of a Reference Architecture GSAW 99 Workshop

Transcription

1 The Value of a Reference ure GSAW 99 Workshop Janis Putman Mike Hooper Andy Reho The MITRE Corporation

2 So Why a Reference ure? MOTIVATION: Need an overarching architecture strategy to accommodate crossorganization incremental system level solutions for a shared environment: frame incremental solution choices to ensure consistent concepts and rules of structure are incorporated into all intermediate solutions. PURPOSE: Provide the basis for making incremental specific design decisions and product choices later on in the system building process. DEFINITION: A high-level parameterized system framework for a system that defines its overall target structure (components and relationships among them) in a systematic consistent manner Influences Reference ure drivers Technical drivers Previous Solution s Interactions Components ure Concepts ure Rules Cost, Risk, Schedule Conformance Test Performance QoS Behavior Constraints

3 Objectives Activity A Cooperative Corporate s Relationships Activity C -wide Properties (example) - Quality of Service - Policies (permissions, prohibitions, obligations) - Autonomy - Cooperation - Execute tasks jointly, - Shared environment - Interoperate, Information Sharing Activity B Cross-Organization Separate s No Central Control - Scalability - Addition of resources (users, system) - Interoperability - Mutual understanding of exchanged messages - Connectivity - Ability of systems to exchange messages

4 Current Challenges Cross-Enterprise Endeavor with: - Incomplete Requirements - Heterogeneous Legacy s - Lack of Interaction Specification - Severe Constraints: Politics, Resource Constraints, Independent Organization Mandates COTS Middleware Complexity ure tools Complexity, Inconsistency, Incompleteness Inadequate and Complex Software ure - ADLs, without commercial maturity and support - Styles and connectors: how do they relate to: each other, APIs, interaction, QoS parameters, networks, actions, etc.? - Few (Integrated) Tools aimed at the architect s problem - UML incomplete: semantics of interaction lacking +graphic tools do not capture all of UML (e.g., ROSE ) - Multiple languages, models, and frameworks for required use, with insufficient consistency - Conformance testing anyone?

5 Reference ure Concepts Resource Management Program Coordination IT Planning Drivers Technical Functional Reqts Reqts Mandates Performance Current Solution Cross-Organizations Cost, Risk, Schedule, ments, Conformance Reference n ure Enterprise Information Application Engineering Technology Policies, Standards, Rules, etc. Incremental Solutions ure n ure 2 ure 1 Target Solution Transitional Processes

6 Incremental Developed Shared of s Guided By A Reference ure Different Increments Different Organizations Different Phases Additional Demonstrations Reference ure Engineer Phase N User Acceptance Engineer Phase N Engineer Phase 2 Engineer Phase N Engineer Phase 1 Engineer Phase 2 Engineer Phase N Engineer Baseline EngineerPhase 1 Phase 2 Engineer Baseline Phase 1 Baseline Phase 1 Phase 2 Engineer Engineer Additional Baseline Initial

7 Increment Examples Enterprise Purpose, Pharmaceutical Management Med Equip Management Information Application Engineering Technology Semantics Functionality Services, Distribution Products Medical Data Semantics Patient Mgmt Public Key Infrastructure Mediators STEP Workflow

8 Use of Reference ure The Aggregation of the Generic RM-ODP Framework and Specific Customer Requirements Viewpoints - provide abstraction - separation of concerns - can be incremental Viewpoint Consistency - architecture evaluation - common understanding - increased completeness and consistency - geographically distant multi-organization can specify and implement separately Govt Example: C2--Actions Information Commander--Role Joint Chiefs--Role Supply--Resources Map--Resources Authority--Permission Responsibility--Obligation Tasking Order--Contract Response Delay--QoS Contractors Govt Enterprise Govt + contractor Application Contractor A Engineering Contractor B Technology Increment n Solution Conformance test

9 Relationships Across Viewpoints (Sample RM-ODP) Enterprise Information Computational Engineering Technology Objects Relationship Role Static Schema Components Interaction Node Cluster Capsule Electr onic Bondi ng Enterprise object Actions Interactions Contract QoS Policy: Obligation Permission Prohibition Invariant Schema Dynamic Schema Interface client/server Interface signal Interface stream Binding Signature Binding Object Contract QoS Relationship rules Functions Managers Transparency Engineering Interface Local Binding Distributed Binding Channel Control Signature Solaris Server SoftDock Oracle 7.2 CORBAORB COM+ Java HTML XML TCP/IP Interworking RP Conformance reference points Interaction Reference Points Programmatic RP 1999 J. Putman, et. al., A Guide to Domain Specific ure with RM-ODP, Macmillan Technical Publishing, ISBN X, ALL RIGHTS RESERVED

10 Summary Reference ure is an integrated framework that only addresses "common" objectives and issues to: - Evolve towards target Corporate system - Integrate legacy and evolving new solutions - Incorporate new IT as it matures - Achieve Corporate strategic goals - Integrate business processes and information technology - Enable shared environment

11 References RM-ODP: ISO/IEC (ITU-T/CCITT X.901-X.903) Australian C4I : C. Herring, Z. Milosevic, S. Kaplan, Selecting Distributed Object Technologies in the Presence of Uncertainty: an Experience Report on C4I enterprise modelling QoS for C2: J. Aagedal, Z. Milosevic, Enterprise Modelling and QoS for Command and Control s, EDOC 98 Federal ITA [Information Technology ure] Conceptual Model, June 1998