We began by envisioning the business and usability goals of the product through meetings and interviews with the development team at the bank. Next, we defined the design constraints by reviewing existing handheld device standards. Since there were already several alternative devices in production, we examined these devices to incorporate best practice in our prototype.
We then developed paper prototypes of the user interface and tested them with end users. This was an iterative process, and we continued to re-design and re-test the prototype until the usability goals were met. Finally, we captured the design in a user interface specification document that the bank could use as a brief for design agencies.
At the end of this engagement, the bank had specific design guidance on how to develop the new, handheld card reader. They also had a good understanding of the product's end users and the tasks they would carry out with the product. And by involving customers in the design of this hand-held product from the very beginning, the bank ensured that customers could achieve their goals without assistance, saving on support costs.