What Is Continuous Availability?

Availability is the probability that the system will be able to operate normally or the expected time occupancy rate at a certain inspection time. When the inspection time is a specified instant, it is called instantaneous availability; when the inspection time is a specified period, it is called period availability; when the inspection time is any time during continuous use, it is called inherent availability. It is a measure of the actual performance of the equipment after it is put into use. It is a comprehensive feature of the reliability, maintainability, and maintenance support of the equipment or system.

Usability

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Availability is the probability that the system will be able to operate normally or the expected time occupancy rate at a certain inspection time. When the inspection time is a specified instant, it is called instantaneous availability; when the inspection time is a specified period, it is called period availability; when the inspection time is any time during continuous use, it is called inherent availability. It is a measure of the actual performance of the equipment after it is put into use. It is a comprehensive feature of the reliability, maintainability, and maintenance support of the equipment or system.

Chinese name

Usability

Foreign name

Availability

Category

Important quality indicators of interactive IT products

Definition

Whether the user can complete his task with the product

Usability is an important quality indicator of interactive IT products / systems. It refers to the degree to which the product is effective, easy to learn, efficient, easy to remember, error-free, and satisfactory for users. How effective is the subjective feeling? In fact, the quality of the product seen from the user's perspective is

The slogan "User Friendly" appeared in the mid-1980s, and this slogan was transformed into the "availability" concept of the adult computer interface. There are many definitions of usability:

The definition in ISO9241 / 11 is: the extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use.).

GB / T3187-97's definition of availability: under the premise that the required external resources are guaranteed, the ability of the product to perform the specified functional state under the specified conditions and within the specified time or time interval. It is a comprehensive reflection of product reliability, maintainability and maintenance support .

Shakel's (1991) definition of usability is more commonly used: usability refers to the "capacity of a technology (according to human functional characteristics). It is easily and effectively used by a specific range of users, after specific training and user support, in a specific environment Scenarios to accomplish a specific range of tasks. "

This definition contains several aspects. First, usability is not only related to the design of the interface, but also to the technical level of the entire system. Second, usability is reflected by human factors and evaluated by users operating various tasks. Third, the environmental period factors must be taken into account. In different fields, the evaluation parameters and indicators are different, and there is no universally applicable evaluation standard. For example, the computer is on the plane, financial management, children at home, online teaching, for experts and new users, for

From

among them:

Effectivenessthe correctness and completeness with which users complete specific tasks and achieve specific goals;

Efficiencythe ratio between the user's correctness and completeness of the task and the resources (such as time) used;

Satisfactionthe degree of subjective satisfaction and acceptance that users experience in using the product.