Everyday we use thousands of different products, from telephones to bikes and drinks cans to washing machines. But have you ever thought about how they work or the way they are made?
Every product is designed in a particular way - product analysis enables us to understand the important materials, processing, economic and aesthetic decisions which are required before any product can be manufactured. An understanding of these decisions can help us in designing and making for ourselves.
The first task in product analysis is to become familiar with the product! What does it do? How does it do it? What does it look like? All these questions, and more, need to be asked before a product can be analysed. As well as considering the obvious mechanical (and possibly electrical) requirements, it is also important to consider the ergonomics, how the design has been made user-friendly and any marketing issues - these all have an impact on the later design decisions.Let's take the example of a bike:
If you do this exercise for various products, you will very quickly discover something interesting...
There are 2 main types of product - those that only have one component (e.g. a spatula) and those that have lots of components (e.g. a bike). Products with lots of components we call systems. For example:
|Bike||Frame, wheels, pedals, forks, etc.|
|Drill||Case, chuck, drill bit, motor, etc.|
|Multi-gym||Seat, weights, frame, wire, handles, etc.|
In product analysis, we start by considering the whole system. But, to understand why various materials and processes are used, we usually need to 'pull it apart' and think about each component as well. We can now analyse the function in more detail and draft a design specification.
To build a design specification, consider questions like the following:
These are only general questions, to act as a guide - you will need to think of the appropriate questions for the products and components you have to analyse. For a drinks container, a design specification would look something like:
Once we have a specification, the next stage in the process is to understand how the materials are chosen.
Given the specification of the requirements on each part, we can identify the material properties which will be important - for example:
|must conduct electricity||electrical conductivity|
|must support loads without breaking||strength|
|cannot be too expensive||cost per kg|
One way of selecting the best materials would be to look up values for the important properties in tables. But this is time-consuming, and a designer may miss materials which they simply forgot to consider. A better way is to plot 2 material properties on a graph, so that no materials are overlooked - this kind of graph is called a materials selection chart (these are covered in another part of the tutorial).
Once the materials have been chosen, the next step is normally to think about the processing options.
It is all very well to choose the perfect material, but somehow we have to make something out of it as well! An important part of understanding a product is to consider how it was made - in other words what manufacturing processes were used and why. There are 2 important stages to selecting a suitable process:
Process selection can be quite an involved problem - we deal with one way of approaching it in another part of the tutorial.
So, now we know why the product is designed a particular way, why particular materials are used and why the particular manufacturing processes have been chosen. Is there anything else to know?
Whilst this approach will often work, design is really holistic - everything matters at once - so be careful to always think of the 'bigger picture'. For example:
Next: Choosing between different materials.
Back: Goals of the tutorial.