I must agree with most of the discussion points mentioned above, but I would like to point out that for an engineer, the DSD would be a must-read document, as we don’t rely on broad descriptions. For example, an engineer will not only tell a certain device works with a 110-volts or 220-volts, but rather would tell you the polarity and amperage. Similarly, a computer engineer would check the compatibility of a piece of hardware before connecting it to the machine. While the DID would be a quick general label that would inform the user about the device, the user would need more explanation regarding the product. Which is why the DSD is very important as it might contain drawings or sketches that would inform the user of all common possibilities that arise when the device is used. It might also contain some suggestions on troubleshooting steps to be taken if a certain problem occurs. It might also demonstrate to the user how a certain calibration process can be performed. Clearly, a good designer must include crystal clear DID and DSD. In a way, the DID and the DSD complement each other, as every point mentioned in the DID must be discussed and explained in details in the DSD. In addition, all of the specifications in the DSD must be verified through carefully conducted experiments.