A Method for Analysing Web Systems Model Alignment

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A Method for Analysing Web Systems Model Alignment

• Presentation at AusWeb 2008
• Andrew J. Bucknell
• Prof. David Lowe
• Prof. Didar Zowghi

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Overview

• We present an approach to aligning Web Systems
  with Organisational Models.
• Our research involves two key components
• Identifying an appropriate notation.
• Providing automated model analysis.
• Two outcomes reported here
• A notation agnostic approach to identifying
  discordances.
• An analysis engine built using a widely-used
  modelling tool (Microsoft Visio).
• Failing to identify mis-alignments early on can
  lead to major delays or cost increases in the
  development process.

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Discordances

• A discordance identifies a mis-alignment in the
  model of a system that, if implemented, would
  result in mis-alignment of the organisations
  processes or information flows.
• Discordances indicate that the introduction or
  modification of a software system will disrupt
  the organisation.
• Discordances arise when aspects of a proposed
  system are introduced or changed without
  appropriate consideration for the impacts on the
  organisation.
• Early identification of discordances allows
  mis-alignments to be addressed before they impact
  on the organisation.

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Discordance - Example

• We use a simple case study to demonstrate our
  ideas.
• The case study allows us to
• experiment with notation elements.
• focus discussions about constraints on a
  practical example
• The example is by no means exhaustive rather it
  is formative.
• Notation is an experimental hybrid of process
  modelling notations and web-system modelling
  notations.
• Example considers making an element of an
  existing timesheet submission process web-based.

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Discordances - Example
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Discordances - Example
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Discordances - Example

• The model of the existing organisational system
  is entirely manual.
• The proposed solution changes elements of the
  process to electronic.
• Entities in the model have attributes indicating
  manual or electronic.
• Analysis of the model of the proposed change
  identifies discordances attributes that are not
  in alignment.
• This indicates that deploying the proposed system
  would disrupt the existing processes.

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Discordances - Example
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Discordances - Example
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Discordances - Example

• Our approach does not prescribe how discordances
  are to be resolved.
• One approach is to change the scope of the system
  to encompass more of the existing system.
• Another approach is to change the scope of the
  proposed system so that it is aligned with the
  existing system.
• When these changes are modelled and analysed, the
  absence of discordances indicates the model
  should be able to be implemented and deployed in
  to the organisation.

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Identifying Discordances

• Discordances can be identified when a pair of
  entity attributes do not satisfy a constraint.
• Constraints apply to related entities.
• ltentity type"Activity"gt ltattribute
  name"inputmedia"/gt ltattribute
  name"outputmedia"/gt lt/entitygt ltentity
  type"Document"gt ltattribute name"media"/gt
  lt/entitygt
• ltrelationship type"Input" from"Document"
  to"Activity"gt ltconstraint fromattr"media"
  toattr"inputmedia"/gt

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Application

• We have implemented a tool that identifies
  discordances by analysing attributes and
  constraints.
• Two goals of the tool
• Serve as a focus for research in to notations.
• Provide a way to apply ideas to real-world
  problems.
• Tool is based on an analytical pipeline.
• Model extraction
• Model analysis
• Constraint analysis

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Application
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Application
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Conclusions

• Discordances in a system can be identified by
  analysing attributes and constraints.
• It is possible to describe attributes and
  constraints in a model agnostic manner.
• Automated identification of discordances can be
  integrated with existing modelling tools.

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Further Work

• Evaluate effectiveness of automated discordance
  identification.
• Evaluate the impact of early discordance
  identification on web-systems development
  projects.
• Continue to develop notation
• Integrate other areas e.g. Real-time systems
  analysis.
• Test current notation against more complex
  systems.

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Summary

• We believe that identifying and resolving
  discordances early reduces the costs associated
  with failed deployments.
• We are investigating appropriate notations for
  modelling systems.
• We have developed a tool that automates
  discordance identification using a commonly
  available modelling tool.

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• Thanks for listening!