EP Specification
The specification defines important aspects of your project. There should be about 12 separate specification points. Electronic parameters are desirable but not essential. e.g.
n The . . . . should operate from a 9V battery.
This is a measurable electronic parameter. A better specification point would be:
n The . . . . should operate from a voltage range of 8V to 9.5V. This is also measurable and takes account of different voltages during battery life.
The following is given by the exam board as an example of a grade A/B specification! Try to improve on it (which should not be difficult!) by including measurable electronic parameters. At this stage, your specification should not include statements that suggest you already have a solution. e.g. It must include a PIC would suggest that you already have a solution to the brief.
n Project must be finished by March 2003.
n The prototype must be safe.
n It must cost less than £5.00.
n Powered by a 9V(DC) battery.
n Circuit must be built on PCB.
n System must have an on/off switch.
n PCB and battery must be secure inside the box.
n All flying leads must be crimped with connectors fitted.
n Battery must have easy access.
n Game must keep young people amused/interested.
n The box must be big enough for a PCB.
n The box must be attractive.
n No sharp corners.
n No small objects.
n Portable.
n Drawers for extra games and loose items.
n Must contain a musical chip.
n Only use the resources available in the department.
n Electronics must be easy to operate.
n It must have a professional finish.
n The prototype must be hard wearing.
n The games must be stable.
The specification is the yardstick against which to evaluate your project at the end.
A good evaluation depends on a good specification!
In writing your specification:
Ø you can refer to the above points and adapt some of the ideas to your project
Ø you can also select from and complete some of the following statements
Ø you can add some statements of your own that define aspects of the project that are fixed and aspects that you are free to change. Some statements in the specification will be very specific, e.g. 'It must be blue'. Other statements may be very open ended, e.g. 'It can be any colour'. Most statements will be somewhere in between, e.g. 'It should be a bright, primary colour'. In this way the statements (or specification points) make it clear what is fixed, and where the designer needs to take decisions.
n My design will need to . . .
n The requirements of the people who will use it are . . .
n It will also need to do the following . . .
n It will be no larger than . . .
n It will be no smaller than . . .
n Its maximum weight can be . . .
n It should be no lighter than . . .
n The following parts of the product should be easily replaceable . . .
For further reference see Design & Make It P16-17