Information Systems and Modelling 1

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Information Systems and Modelling 1

• Week 1 Lecture 1 Autumn Semester

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Lecture Summary

• How to build models
• Hard / soft model
• Iconic / Analogic / Symbolic models
• Dynamic / Static models

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How do we build good models?

• Tutorial exercise
• We should follow these steps whether this model
  is physical or computer-based!
• Sometimes it is too easy to change computer-based
  models

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What is a model?

• A model is a representation of the environment
  around us
• Hard / soft model
• Iconic / Analogic / Symbolic
• Dynamic / Static

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Hard Model

• Represents some system
• Problem definition has single objective
• People and organisation not included
• Quantitative data
• Goal is to solve problem or to optimise
• Outcome is product or recommendation

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Soft Model

• Generates debate / insight into system
• There may be ambiguous objectives
• There may be more than one objective
• People and organisation are integral
• Qualitative data
• Goal is to provide insight and learning
• Outcome is progress through group learning

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For this module we are going to concentrate on
hard models. For future modules you may need
to be aware of and consider soft models.

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What is a model?

• A model is a representation of the environment
  around us
• Hard / soft model
• Iconic / Analogic / Symbolic
• Dynamic / Static

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Iconic Models

• Physical resemblance to reality
• Various uses and goals
• Pleasure
• Art, Photography
• Business needs
• Advertising, Marketing
• Architecture, Engineering, Science
• Scale models

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Analogic Models

• Physical Representation of quantitative data
• Data is changing
• Speedometer
• Converts revolutions of wheel to speed which is
  shown on meter on dashboard
• Close, but not always accurate representation of
  data

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Symbolic models

• Physical attributes can be measured and converted
  into mathematical abstractions
• e.g.Model of bridge
• Weight of vehicles, Effects of high winds
• e.g.Customers in checkout queues
• Time between arrival of customers, open / closed
  tills
• Symbolic model can check out these phenomena
  using maths

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For this module we are going to concentrate on
symbolic models where we model mathematical
abstractions of systems.

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What is a model?

• A model is a representation of the environment
  around us
• Hard / soft model
• Iconic / Analogic / Symbolic
• Dynamic / Static

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Dynamic model

• Model that changes over time
• Environmental models
• e.g. Weather forecasting models
• Business models
• e.g. Changes in availability of stock

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Static Model

• Models which are built once and do not change
• Engineering models
• Models of houses, bridges, towns

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For this module we are going to concentrate on
dynamic models where we can make changes to the
mathematical abstractions of systems.

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Hard modelsSymbolic models Dynamic models

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Lecture Summary

• How to build models
• Hard / soft model
• Iconic / Analogic / Symbolic models
• Dynamic / Static models
• Tutorial
• Examine one model. Categorise it within the
  three options above. What happen(s/ed) if it is
  right? What happen(s/ed) if it is wrong?