Software Architecture A Roadmap

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Software Architecture - A Roadmap

• Author - David Garlan
• Presented by - Ashish Grover

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Agenda

• Introduction to Software Architecture
• Roles of Software Architecture
• Older techniques
• Current techniques
• Supposed future
• Embedded Software
• Conclusions and review

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Introduction to software Architecture

• The software architecture of a program or
  computing system is the structure or structures
  of the system, which comprise software elements,
  the externally visible properties of those
  elements, and the relationships among them.

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Software Architecture as a Bridge
Requirements
Software Architecture
Code
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Roles of Software Architecture

• Describes a systems gross structure
• Composure of system as a collection of
  interacting parts
• Main pathways of interaction b/w parts
• Key properties of parts

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Imp role in six aspects

• Understanding of system
• Reuse at different levels
• Construction
• Evolution
• Analysis
• Management

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Antecedents of Software Architecture
Courtesy David Garlan
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Older Techniques

• Informal box and line diagrams
• New design evolved from previous designs
• No technique to
• Do analysis for consistency
• Check implementation is in accordance with
  architectural description

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The two trends

• Shared set of methods, techniques, patterns
• Use of metaphors such as client server system
• Significant semantic content which reasoned about
  their paradigms, evolution, relationships and
  concerns
• Searching similarities in specific domains to
  reuse frameworks
• Some examples are frameworks, 4GLs, UI toolkits

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Current Techniques (Yr 2000)

• Recognition of s/w architecture as a sub-field
• Organizations now have software architects who
  chair the architecture review boards
• Emerging use of product line architectures,
  commercial architectural standards, component
  integration frameworks
• Codification of vocabulary, notations tools for
  architectural design
• Books/courses on software architecture

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Current Techniques (contd.)

• Three significant advancements
• Architecture Description Languages
• Product Lines and Standards
• Codification and Dissemination

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Current Techniques (Contd.)

• ADL
• Required for formal analysis of consistency,
  completeness or correctness, enforcing
  architectural constrains with system evolution
• Provide framework and syntax for characterizing
  architectures
• Provide tools for parsing, compiling and
  simulating architectural description
• Different ADLs provide distinct capabilities

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Current Techniques (Contd.)

• Product Lines Standards
• Exploiting commonality across products
• Creating product lines within an organization
• Cross-vendor integration standards

Product Requirements
Product Architecture
Product Line Architecture
Product Line Requirements
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Current Techniques (Contd.)

• Codification and Dissemination
• Using standard architecture styles
• Styles provide a design vocabulary, assumptions
  and constraints on the use of the vocabulary
• Styles are a good starting point for software
  architects

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Supposed future

• Future architecture will follow the current
  trends in industry.
• Build Vs Buy
• Requirement to decrease time to market
• Vendor built components come in picture
• But this requires components built on industry
  accepted standards
• Integrating in-house components with vendors
  components is a nightmare

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Supposed future (contd.)

• Network-Centric Computing (challenges)
• No centralized control
• Need for architectures which scale
• Architectures which do not rely on resources as
  resources can be mobile
• Architectures which handle dynamically evolving
  components
• Accommodate commercial application service
  providers

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Supposed future

• Pervasive Computing (Challenges)
• Architectures suited for resource constrained
  environments
• Dynamically reconfiguring uninterrupted service
  providing architectures will be need of hour
• Handle user mobility

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Types of Embedded S/W Architecture

• Control Loop
• Non Preemptive Multitasking
• Preemptive timers
• Preemptive tasks
• RTOS

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Diagram of an ARC integrated software platform
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Conclusions

• Points for
• S/W architecture development timeline analyzed
  properly
• Lot of examples discussed
• Speculated future work then has really become
  active research areas of today
• Foresees challenges that might be issued in
  future environments

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Conclusions (Contd.)

• Points against
• Detailed but abstract paper
• Completely forgets other kind of future
  environments and constraints
• Security components?
• How to approach towards building systems for
  these new environments?

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References

• http//www.cs.ucl.ac.uk/staff/A.Finkelstein/fose/p
  resent/garlanpres.pdf
• http//www.arc.com/evaluations/29B12561.1_SW20Cap
  abilities_8-09-04_final.pdf
• http//www.brainyencyclopedia.com/encyclopedia/e/e
  m/embedded_system.html
• http//www.iec.org/online/tutorials/vocable/topic0
  6.html
• Foundations for the study of software
  Architecture by Dewayne E. Perry and Alexander L.
  Wolf
• http//www-2.cs.cmu.edu/able/presentations/columb
  ia-1-01.pdf

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• Questions ?