Is a good brief one that states exactly how a product should be configured or designed? Perhaps not.
The brief should state the constraints the product may have, possibly some manufacturing limitations, but not exactly how the product should be designed, configured or made.
This may be semantics, but a brief should not be too specific on the details, but rather the desired result.
By way of example: would a good brief be to design "a portable speaker that clamps to the handle bars of a bicycle" or "a portable device that provides music accompaniment to the cyclist"?
Even if the electronic componentry of the two were the same, the latter allows for greater freedom of innovation.
In the first case we have a speaker clamped to the bars of bicycle; however the latter offers more opportunity, and the device could take any form and attach anywhere on the cyclist or bicycle, bringing the brief back to the consumer need — and then some more.
Allow for boundless innovation and creativity
Industrial design consultancies generally work on a spectrum of projects in diverse materials using many different production processes, and this allows them to bring innovation to the table if the brief makes allowance or even encourages this.
I have had many cases of clients providing a brief of exactly how the product should be configured or made rather than what it could be. After dissecting the brief, we have been able to establish its essence, open it to innovation, and in some cases – patentable products. We have been able to look at new opportunities that could arise from a different approach or solution.
Innovation also does not necessarily mean developing a totally different product either, but it could be in the way the product is manufactured or assembled – perhaps making it easier or with a smaller part count. It could be the way the product is used or interacted with or possibly just even simpler.
You don't go to an industrial design consultancy just to get a "sexy" looking product, but rather a product with an advantage, and one that has some innovation. A good brief should promote this.
So unless you are just recreating an existing product, write a brief that allows for creativity, lateral thinking and innovation.
Also, get a consultancy that knows what to do with an innovative brief.