TABLE OF CONTENTS Most designs start with a sketch often on the back of an envelope. In order for them to evolve and reach production some communication is necessary. In some cases giving the sketch to a craftsman could be sufficient; however, this is not generally the case!
The development and evolution of electronic systems can be speeded up by the use of the right tools. It is important to recognize which tools are suitable and to understand their limitations. There is an oft-quoted phrase garbage in garbage out (GIGO) meaning if you put bad or erroneous data into a computer it will give you back bad answers.
The design process usually consists of four recursive stages: the initial problem; the idea for the solution; implementation, testing and refinement of the idea; and deployment of the solution. If you work entirely on your own and have a good memory, possibly you would never need to document any of the stages; however, as soon as other people or systems become involved some kind of communication is necessary to convey your ideas to others.
Until quite recently a sketch on the back of an envelope would have been converted to a pen-and-ink drawing on paper of some standard size and filed so that when necessary it could be copied and distributed to communicate the idea. The users of the drawing would probably have marked changes and corrections on it and sent it back to the drawing office to be completely redrawn. The...
