Analysing Real World Systems

This Masters level course unit to introduce the task of the modeller, was developed with Terry Hinton for teaching at the University of Surrey, using the Computers in the Curriculum Pipe simulation and Stella, the dynamic modelling system as examples.

When	Jun 13, 1991
Where	Guildford, Surrey

This is an extract from the beginning:

Unit 3 Analysing Real World Systems

1 - INTRODUCTION

In this module, the process which the modeller undergoes is discussed in order to understand better the decisions that must be taken when setting out to model a real world system.

These decisions are critically influenced by the purpose the model is to be put to and by the tools chosen to implement the model (and then simulate the real world system).

There are several questions facing the modeller at this point:

How do you decide what aspects of the real world matter?

How do we simplify these aspects and reduce them to the kinds of objects which a modelling system can represent and manipulate?
What representative values do we take from the mass of data that can be gathered?
What variables do we define to contain these values?
What relationships do we propose link these variables?

These questions are about mapping the real world onto the objects, functions and processes available in the modelling tool used.

A problem for every analysis of a real world system is how to represent time. There are models (and simulations) in which time takes no part, but usually time is a key variable on which many other variables depend. There are a range of methods for representing time in a model and choosing the method is important for effective simulation.

2 - UNIT AIMS AND OBJECTIVES

Aims:

To introduce the process of analysing real world systems and the relationship between this process and the modelling tools available.

Objectives:

By the end of this unit, participants should:

to be able to explain in general terms of the modelling process;
be able to choose appropriate tools for modelling tasks;
be aware of the alternatives for mapping real world entities and relationships to modelling system objects and functions;
understand the importance of time in modelling and simulation.

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