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Study guide

Click on the headings below to expand the study guide.

Introduction

In this learning outcome you will study some basic ideas on engineering design.  You will look at a manufactured product and analyse it to find out about its design.

Engineering design

The job of an engineer is to find cost effective solutions to problems.  Designing a new bridge over a river is a very different problem to designing a new electric toothbrush, but there are often similarities in the steps taken in all engineering designs.  Here is one way of thinking about the engineering design process:

However, design is seldom a linear process.  Rather, it is iterative where steps are repeated until the best solution has been found.  For example, modifications to a design might be required after a prototype has been built and tested, or difficulty in manufacturing a product might mean another concept needs to be tried.  Here is a development of these ideas from the UTeach Engineering project at the University of Texas:

'A Unique Approach to Characterizing the Engineering Design Process' Copyright  UTeach (2011)

Used under Fair Dealing

As well as functional requirements, the design of many products must also consider aesthetics and ergonomics - how a product looks and how easy it is to operate.  

Activity 1

Reverse Engineering

Reverse engineering is when a manufactured product is examined in great detail to see how it works and how it was made.  With this knowledge, it could then be reproduced or improved on by another manufacturer. 

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Reverse engineering has obvious problems with intellectual property rights but it is widely practised (legally) in many industries.  

Activity 2

In this module we will use reverse engineering to examine a manufactured product and find out about:

1. The specifications of the product and what it does
2. The components that make up the product, their functions and how the whole product works
3. The materials used in the product and how it was made.

In other words, the design of the product will be analysed.  A detailed understanding of the product will then allow its design to be evaluated.  For example:

• Why were specific components selected? Were there any alternatives?
• Why were specific materials selected? Were there any alternatives?
• Which manufacturing processes were used? Were there any alternatives?
• How was the product assembled?
• What were the priorities in design? Manufacture? Maintenance and repair? Aesthetics?
• How could the design be improved?

Activity 3

Activity 4

Materials selection

An important part of design is choosing the best material for a particular component.  A design engineer has to decide on the properties the material needs to have, perhaps consider a number of different alternative materials and then choose the most cost effective one. 

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Activity 5

Activity 6

Design engineers a need a methodical approach to materials selection.  One method is to:

1. Decide which properties are required and prioritise them by assigning each a weighting.
2. Identify a number of alternative materials that might be suitable. Evaluate each material against the properties required, using reliable data where possible.  For example, if stiffness is required find out the elastic modulus of each material.
3. Collect the information in a table and add up the weighted performance for each material in each property to find the “best” material.

An example is shown below, where this exercise was carried out for a fitting used to join two high pressure hoses:

Activity 7

Coursework Guidance

Choosing an engineering product to investigate

There are three broad options:

1. Perhaps something suitable is available that can be dismantled fairly easily. Choose something old or broken because it may not be safe to put it together after you’ve finished and use it again.   Things like old power tools, CD players and domestic appliances would be good.
2. You may have something that can be examined as it is or with minimal disassembly so there is no risk of breaking it. Maybe all components can be seen without dismantling, or a cover can be removed to reveal the components inside.
3. You carry out a “desk top” investigation rather than dismantle a physical product. This has to be on a specific example of an engineering system, rather than something generic.  So if you want to investigate wind turbines choose a specific model, for example Vestas V150-4.2MW.

In any case, you will need to know the basic specifications of the product so choose something for which you can obtain information.  Manufacturers’ data sheets or brochures are useful for this.

Activity 8

Choosing an Engineering Product to Investigate

There are three broad options:

1. Perhaps something suitable is available that can be dismantled fairly easily. Choose something old or broken because it may not be safe to put it together after you’ve finished and use it again.   Things like old power tools, CD players and domestic appliances would be good.
2. You may have something that can be examined as it is or with minimal disassembly so there is no risk of breaking it. Maybe all components can be seen without dismantling, or a cover can be removed to reveal the components inside.
3. You carry out a “desk top” investigation rather than dismantle a physical product. This has to be on a specific example of an engineering system, rather than something generic.  So if you want to investigate wind turbines choose a specific model, for example Vestas V150-4.2MW.

In any case, you will need to know the basic specifications of the product so choose something for which you can obtain information.  Manufacturers’ data sheets or brochures are useful for this.

Product dissection

If you’re going to dismantle something for this coursework you need to work safely and methodically.  In reverse engineering it is important that all steps are clearly recorded. 

Activity 9

Investigations

Here is some broad guidance on your investigation:

Report Format

By the end of your investigation you will probably have learnt a lot and gathered a great deal of information.  It is important that your report is a good reflection of all the work you have done, so give yourself time to do it properly. 

Activity 10