In this section we will discuss the pathway of device development and how user requirements should be considered and captured during it. The issues that should be considered at each stage will be identified as well as how these should be investigated. By the end of this section you will be able to identify the points in the development of your device that require the consideration or active involvement of users as well as to decide upon the research questions that need to be answered at each of these stages.



Figure 1. illustrates a typical device developmental pathway; this is intended to identify the stages of device development and to show how consideration of user requirements should map onto each stage. The entry point into this pathway will vary. For example the need for a new or improved device may already be known and development may move directly to the validation stage, but most of the steps and processes in this figure will be relevant at some point during development.

The blue boxes show the different stages of development and what the aims of the user requirements work should be at each stage. The hexagons show what the targets or outcomes for each of these stages should be, the hexagons may also be the points in development where a decision is made, for example to carry on with development, to abandon development, to change the direction of the project or to put development on hold.

Broadly speaking, the first two stages can be seen as identifying what the requirements are for the device, and the second two stages ensuring that the device meets those requirements. Each stage of development will now be discussed in detail, including the issues that should be considered at each stage.