1.6 A PDS checklist

The product design specification, or PDS, should contain all the facts relating to the product. It should not lead the design by presupposing the outcome, but it must contain the realistic constraints on the design. This list is one attempt to cover the principal questions that need to be answered in formulating a PDS. Inevitably, it isn't comprehensive; specific products will require their own additional items.

1. Performance

   At what speed must it operate?

   How often will it be used (continuous or discontinuous use)?

   How long must it last?

2. Environment (during manufacture, storage and use)

   All aspects of the product's likely environment should be considered: for example temperature, humidity, risk of corrosion, vibration.

3. Target product cost

   This is strongly affected by the intended market.

4. Competition

   What is the nature and extent of existing or likely competition?

   Does our specification differ from the competition?

   If so, why?

5. Quantity and manufacture

   Should it be made in bulk, in batches, or as individual items made to order?

   Does it have to be a particular shape?

   Can we make all the parts or must we buy some in?

6. Materials

   Are special materials needed?

   Do we have experience of working with the likely candidate materials?

7. Quality and consistency

   What levels of quality and consistency does the market expect for this product?

   Does every product have to be tested?

8. Standards

   Does the product need to conform to any local, international or customer standards?

   Is the product safe?

9. Patents

   Are there any patents we may either infringe or register?

10. Packaging and shipping

    How will the product be packaged?

    How will the product be distributed?

11. Aesthetics and ergonomics

    Is the product easy and fun to use?

    Is it attractive to the right customer?

12. Market constraints

    Does a market already exist or must it be created?

    What is the likely product lifetime?

    How long do we have to get the product to market?

    What are the customers' likes and dislikes?

13. Company constraints

    Does the product fit in with company image?

    Are we constrained in material or process choice?

    Are there any political considerations?