Technology characteristics can be grouped into two main categories — technical characteristics and context of use.

7.6.2.1 Technical characteristics

These are concerned mainly with the advantages and disadvantages of specific technologies and the human factors considerations. These would include the performance criteria listed below. Most advantages and disadvantages of technology can be evaluated objectively simply by comparing features and performance measurements. However, such measures are often meaningless if not performed with reference to the specific context of use, described below.

Other practical aspects of technology choices would include the following:

• cost of ownership (including cost to maintain and replace);

• availability (is the product actually available and how long will it take to procure?);

• technical performance (how does the product perform on specific measures such as accuracy, sensitivity, resolution, reliability, etc.?);

• environmental constraints for operation (can the product withstand rough handling, dirty environments, etc.?);

• compliance (does the technology meet applicable standards, such as Occupational Safety and Health Administration (OSHA)?);

• Training required (how difficult is it to learn?);

• system variables (processing power, memory size, power requirements).

In addition to these characteristics, we can identify a number of complementary categories that must also be considered when selecting technologies. These application criteria are called the engineering ‘ilities’:

• Usability — As defined in ISO 9241-11 (1998), the effectiveness, efficiency, satisfaction and safety with which specific users can perform specific tasks in defined contexts.

• Maintainability — This is the ease with which a product can be maintained. It is also a

characteristic of design related to the amount of time taken to return a failed piece of equipment back to its normal operable state.

• Accessibility — This is a measure of how easy it is to obtain the device, tool, function or information when needed.

• Operability — This refers to a device being ready for use or to be placed into service, or the ability to keep equipment or system in a safe and reliable, functional condition.

• Reliability — This is the ability to consistently perform an intended or required function and mission and the probability that a given item will perform its intended function for a given period of time under a given set of conditions.

• Durability — How well a device is able to perform and withstand a variety of conditions by resisting stress or prolonged use.

• Simplicity — How easy it is to understand, explain and operate a device or system. We can also associate simplicity with intuitiveness and usability of a device or concept.