User-Centred Requirements Handbook |
The aim is to capture information about the future physical environment. This includes, for example: workstation layout, workplace design and physical conditions (the visual, thermal, auditory and atmospheric environments, as well as environmental stability.)
Process
To assist in capturing details about the physical environment, Form 1.5 should be completed by carrying out the following steps:
1. Fill in name of system and user group at the top of the form.
2. Fill in the first column ('Characteristics') of the form completing all relevant physical environment characteristics.
3. Consider each of the characteristics in turn and write down any user-related implications ('Potential user requirements') for the design of the system in the second column. These will become provisional user requirements for the system.
4. Review each of the implications for design and assign a reference number to it. This will allow the information to be traced back to this original table. Where a characteristic has two or more user-related implications for the design, give each a separate reference number.
Physical characteristics include the following:
Thermal and atmospheric environment
• If the system is to be used in the open, for example, an electronic ticket machine or timetable system for the public, then it will need to be designed for all weathers. This will include specifying the system to resist rain, moisture and temperature extremes. This may have implications such as users wanting to wear gloves and being able to use the system keyboard at the same time.
Auditory environment
• The level of sound that takes place may have an impact on the use of the system and it may be necessary to specify ways of damping down sound. For example in a lorry, the engine sound may hamper the driver's mate from communicating by radio to the control centre.
Vibration or instability
• Vibrations are a common problem for travellers and can hamper activities of both drivers and passengers. It is necessary therefore to determine the level of vibration and to ensure that account is taken of it in designing system controls.
Visual Environment
• The visual environment will also affect people's ability to use a system, and both low and high levels of lighting can impair the user. A public information system, for instance, must be usable both during the day and at night. Sunlight may produce glare on the user's screen. Details of the visual environment must therefore be recorded in order that potential user problems will be considered.
Space and furniture
• The characteristics of the current installation place must be studied so that the user will have enough space to operate the system safely and comfortably.
User posture
• The postures that the user will generally adopt when using the system should be recorded (e.g. standing and looking down at a display, height 1.5m) in case there are any implications for system design.
Location
• Here it is necessary to consider where the system will be located in relation to the workplace, and where the workplace is located. It may be important to consider how close this location is or needs to be to the target areas of influence, resources, fellow work colleagues, customer's and possibly the user's home.
Health and Safety hazards
• Any health and safety conditions must be considered so that safeguards can be built into the user needs analysis activity. In this way, suitable safeguards can be incorporated into the user requirements specification.
Protective clothing and equipment
• Here should be recorded any protective clothing or safety equipment that the user may be wearing, either by preference (e.g. winter clothing) or as a requirement of the job in the workplace. This includes items of clothing or equipment which protects the user from the effects of high or low temperatures.
Form 1.5 - Physical Environment (Example)
| 1.5 Physical Environment | |||
| System name:Bank machine | Form completed for user groups selected in Form 1.2 | ||
| User group:General public | |||
| CHARACTERISTICS | POTENTIAL USER REQUIREMENTS | REF. | |
|
Thermal and atmospheric environment UK outdoor weather: conditions. |
Equipment should work in the following conditions: Temperature -10c to +40c Humidity 55% - 90%, Rainfall |
1.5.1 | |
|
Auditory environment UK urban street |
Any use of auditory feedback or output may be drowned by street noise unless some form of earpiece or volume control is available. | 1.5.2 | |
|
Vibration or instability Not applicable |
|||
|
Visual Environment Will be used during the day and night. Sunlight may produce glare on screen. |
Sighting of machine should avoid glare where possible. Screen filters and matt screen surfaces should be tested to see if they reduce potential problems. Needs to be luminescent for use in the dark. | 1.5.3 | |
|
Space and furniture Bank machine should be easy to reach for a wide range of members of the public. | Bank machine should be mounted 1m. above ground, inset into the wall. | 1.5.4 | |
|
User posture Bank machine will normally be used standing. Wheelchair users will be sitting. |
Bank machine should be reachable by at least 80% of wheelchair users both in terms of height and posture when operating the machine. | 1.5.5 | |
|
Location Street, public thoroughfares |
Ensure machine is clearly visible and signposted for people trying to locate it. | 1.5.6 | |
|
Health and Safety hazards Danger of robbery and mugging of people withdrawing cash. |
Position bank machine in the open and with extra lighting to maximise safety. | 1.5.7 | |
|
Protective clothing/equipment Winter clothing would include gloves, muffs etc. |
Keys should be operable by users wearing gloves. | 1.5.8 | |
Transfer to Form 3.8 Physical environment