Modelling

Introduction

Modelling is the process of developing a representation of a real world issue, system, or situation, that captures the aspects of the situation that are important for a particular purpose, while omitting everything else. Examples: London Underground map; storyboards for animations; a web ”site map”; the position, mass, and velocity of planets orbiting one another.

Different purposes need different models. Example: a geographical map of the Underground is more appropriate for estimating travel times than the well-known topological Underground map; a network of nodes and edges can be represented as a diagram, or as a table of numbers.

A particular situation may need more than one model. Example: a web page has a structural model (headings, lists, paragraphs), and a style model (how a heading is displayed, how lists are displayed). A browser combines information from both models as it renders the web page.

Simulation is a subset of modelling.