Secondary 2: Dining Storage Accessories Project - Design Considerations & Limitations + Design Specifications

This part of the design process is right after you have written your Design Situation and Design Brief. 

Design Considerations and Limitations

The 'Design Considerations and Limitations' (or Constraints) can be liken as 'what factors should I consider'. Thinking of it in this way will make completing this task slightly easier.

Limitations or Constraints refers to factors that will 'restrict' you in making the product. Some factors that are considered 'limitations' or 'constrains' or 'restrictions' are for example, time, cost, size, technological feasibility (i.e. the available type of machines and tools in the school design workshop), so on and so forth.

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Imagine you need to plan for a class outing. You will need to plan and create a list of stuffs you need to do (or consider bringing). You do not need to go into the details yet but generating an initial list from which you can work out in details later. For example, you'll need to consider to 'bring some bottled drinks', then 'plan the routes to the destination', etc. 

In a similar way, you would have already chosen a particular type of 'storage' or 'holder' you want to design for. Recall your Design Brief. Now think, "I want to design and make a ..." so "what are the things/factors I must 'consider'?"

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Examples of common factors related to a proposed project

'I must consider..."

'functionality': what you want your product to do or how you want your product to work)

'size': this could be the area of the space you want your product to be placed, or the overall size of the product you will eventually make.

'materials': this can refer to the type of materials that you are given or the quantity.

'time': in a project you are usually given a period of time to complete your work. so considering the time you have is important as it will influence the way you spend your time and design your product. so that you can complete it in time.

etc. You can read more about the other factors by referring to your textbook. 

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Critical Dimensions:

The critical dimension is part of research and it is an important one to consider. For example, I want to design and make a 'business card' holder. Before I begin generating ideas and such, I got to have some important data on standby for me to make some design decisions later. 

One common dimension that you must have is the dimensions of the 'things' you plan to hold or store. If I plan to make a holder / storage for business cards, I should research on the sizes of a typical business cards. I might go as far as measuring the thickness of a single card, or multiples of 5 cards all the way to 20 cards, or so. The more variety of ways to measure and better. Because I do not know if I will need them. Who know?

If yours is a straw holder, then measure the straws. A single one and a bunch of them. If yours is a spoon and fork holder, then measure them too. For the rest it is the same. Measure them. Weigh them. Whatever data you can record.

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Design Specifications

I like to think of Design Specifications as a 'wish list'. 

It sounds more 'friendly' and less daunting than 'Design Specifications'. So technical.

The design specifications are a list of very specific instructions that comes from your list of design considerations. Can you still remember design considerations as a 'list' of factors which you need to 'consider'? They were not detailed at all. Or not detailed 'yet'. 

When I say 'I need to consider the quantity of cards for the business card holder', I have not specified 'how many'. In design specifications is where you state 'how many'. In design specifications you will also state how 'big / small' (e.g. area or volume), how 'cheap / expensive'(e.g. cost), how 'long / short' (e.g. time or length), how 'heavy / light' (e.g. weight), etc.

In the example above, I will be very specific to say, 

'The product must hold (at least) 15 business cards'. 

Nothing more than 15. The number 15 is a very specific number.

You can also put numbers on factors that is concerning efficiency, or fast or quickly or ease o use. You use 'time' to quantify efficiency. You can say,

 'The product must be easy to use. The user must not take more than 5 seconds to refill all the 15 business cards into the holder when it is empty'.

Shown above are two examples on how you can complete your Design Specifications. 

Refer to your textbook if you still have problems completing this section.