User-Centred Requirements Handbook |
In this section, any design constraints or areas of flexibility that will apply to the new system are listed. These may include statements such as that 'it must be handheld', 'it must not use more than 12 keys', 'its maximum storage capacity is 100 A4 pages'.
It will be important to clarify these constraints before design starts and it is later found that proposed design concepts cannot be implemented.
Some constraints may in fact define flexibility, in order to open-up possibilities for the design team. For example, the number of keys may be fixed by the layout or may be flexible.
Process
1. Review the project documentation so far prepared and try to identify possible constraints that will affect the user. These may be in terms of hardware, likely response times, memory, or technology already being used in the user environment.
2. List these constraints in the table below:
Form 2.2 - Design Constraints (Example)
| 2.2 Design Constraints | |
| System: Bank machine | Ref. |
| System will be based on standard bank machine terminal. | 2.2.1 |
| Screen size will be standard 10 inches, with a resolution of 640x480 | 2.2.2 |
| There will be 8 screen buttons for soft keys, 4 down each side of the display | 2.2.3 |
| There will be a keypad of no more than 16 keys. Configuration is flexible. | 2.2.4 |
| Colour of keys is flexible | 2.2.5 |
Transfer to Form 3.4 Technical environment