The NEXOF Reference Architecture for Servicebased Systems

1
The NEXOFReference Architecturefor
Service-based Systems

• Steano De PanfilisEngineering Ingegneria
  Informatica S.p.A.
• The Service and Software Architectures,
  Infrastructures and Engineering (SSAIE) Summer
  School
• 16-19 June 2009 - Heraklion

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Outline

• NEXOF and NEXOF-RA
• NEXOF Reference Architecture (definition)
• Architecture Design Process
• Reference Architecture Structure

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Services propose a single reference model

• Context ISTAG Model

Business Services
Internet of Services
Global Service Delivery Platform
Networking Services
Internet of Things
Devices and components
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NEXOF main concepts

• NESSI Open Service Framework
• Open Reference Model
• Concept and Principles
• Open Reference Architecture
• Standards
• Open Reference Implementation
• Conformance Test Suite

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NEXOF-RA Research challenges

• Provide an holistic approach to architecting
  GSDPs
• Provide a uniform view and approach to a GSDP
• Make GSDP models (conceptual and architecture)
  useful
• From user requirements to specific GSDP
  instantiations
• Properly instantiate in specific domains
  (business domain and size)
• Implement only the required functionalities
• use specific technologies (software, SaaS, etc.)

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NEXOF layered Functional View
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Contributing to NEXOF
NEXOF Community
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Reference Architecture definition

• The NEXOF Reference Architecture is
• An open, coherent, consistent and comprehensive
  set of concepts and specifications
• A guide for system architects to design
  architectures of service-based software systems
  which, in turn, provide solutions to a well
  defined set of requirements.
• The NEXOF Reference Architecture purpose is to
• Consolidate selected innovations in the area of
  service-oriented architectures and technologies
  to facilitate the precise implementations of
  interoperable service environments
• Offers an attractive foundation on which to build
  further innovation
• Allow the identification of gaps to be addressed
  by further research

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NEXOF Reference Architecture
Research
Adoption
SRA
Open, coherent, consistent and comprehensive set
of concepts and specifications
Guide to facilitate the precise implementations
of interoperable service environments meeting
requirements
24/11/2009 - v 1.0
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Reference Architecture Requirements

• Open3 (open, open, open)
• To contributions ? integration mechanism
  (structure and process)
• To adoption ? licensing policy (open with
  derivative rights)
• To evolution ? evolution and disruptive changes
  over time
• Independence Principle
• Technology
• Business domain ? one-size does NOT fit all
• Business scale
• Unity Principle
• Integrated
• Consistent ? unified construction approach
• Coherent
• NOTE This is not the full list of requirements

24/11/2009 - v 1.0
10
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NEXOF-RA Conceptual View

• The NEXOF Reference Model (v1.0)
• From 9 concernsto 125 functionalities
• 100 of which fromexternal sources(standards,
  NSPs, ITs)
• High overlap with FI FR

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Industrial Advisory Board Input

• Strong endorsement of the objective with a
  caveat (boil the ocean)
• Strong endorsement of the openness principles
  and actions
• Some by-products can be very useful (neutrality
  in execution)
• Recommend to focus on barriers to adoption of
  service technologies
• Recommend to innovate on communication be
  specific, use cases,
• Developing services should be easy!

24/11/2009
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RA how?

• Which kind of content
• is the specification
• constituted of?

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contains ...

• Constraints that NEXOF compliant platforms must
  satisfy
• interfaces of components and platform
• inter-operability at component, platform and
  business level
• Recommendations to help the design of NEXOF
  compliant platforms
• quality properties

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NEXOF-RA Specification

• The NEXOF-RA Specification will result into a set
  of architectural patterns to meet specific
  requirements
• Each pattern, on the basis of specific
  requirements to meet, will provide constraints on
  which functionalities the system must provide and
  recommendations on how to achieve a certain
  functionality in a particular level of quality

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constructional patterns

• A complete system cannot, nor will ever, be built
  from a single pattern. It is the integration and
  composition of patterns that makes a whole
  system.
• NEXOF-RA Specification will adopt a structural
  approach to use patterns as first class design
  elements, that is they can be used in the
  designing of a system as any other design
  element class, module, component. This kind of
  patterns are called constructional patterns
• Thomas Erl http//www.soapatterns.org

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costructional patterns properties

• Effective each pattern is designed to meet
  specific requirements
• Integrable patterns can be composed (dual
  patterns)
• Adaptable patterns may be further specialized by
  different alternative patterns (sub-patterns)

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Architecture Design Process
Reference Architecture
Requirements, needs, demands
Design Activity
(produces)
(Description of) System Architecture
(property of)
Service-Based Software System
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NEXOF Reference Architecture Structure
Reference Specification
Standards Catalog
Pattern Ensemble
Guidelines and Principles
Top-level Patterns (system families)

• About
• construction principles
• reference properties
• instantiation guidelines

Component Catalog (aka. Building Blocks)
S
Reference Model
Abstract (class of products)
Concrete (refers to products)
Abstract Design Patterns
Glossary
S
S

• About
• actors
• functionality
• information

Implementation Design Patterns
Conceptual Model
S
S
Reference Architecture
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NEXOF Reference Architecture Structure
Reference Specification
Standards Catalog
Pattern Ensemble
Guidelines and Principles
Component Catalog (aka. Building Blocks)
Reference Model
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NEXOF Reference Architecture Structure
Reference Specification
Standards Catalog
Pattern Ensemble
Guidelines and Principles
Top-level Patterns (system families)

• About
• construction principles
• reference properties
• instantiation guidelines

Component Catalog (aka. Building Blocks)
Reference Model
Abstract (class of products)
Concrete (refers to products)
Abstract Design Patterns
Glossary

• About
• actors
• functionality
• information

Implementation Design Patterns
Conceptual Model
Reference Architecture
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Conclusions

• The NEXOF Reference Architecture Structure
  defines a lower level of details
• Reference Specification structure introduced
• Level of granularity defined for RS(building
  block / construction kit approach)
• Defined structural links between architecture
  aspects
• www.nexof-ra.eu