There are six quality attributes often, availability, modifiability, performance, security, testability, usability.
(1) Availability (Availability)
Availability is the ratio of the system uptime is measured by the case where the speed of operation can be restored to normal length of time between system failure or crash. Next we Taobao as an example:
Scene: In the shopping carnival
Stimulus: Online users colleagues
Irritation: large number of users into the system, causing the system to crash
Article: a processor system crash collapse
In response to: make the corresponding record, the feedback error information, system status holding
Response Metrics: The system returns to normal
(2) can be modified of (Modifiability)
Concern two concerns: What can be modified? When and who to be modified.
To Taobao, for example:
Scene: the user to modify address
Stimulus: User
Irritation: replace the need to change the user's address
Products: user interface
Environment: Operating
Response: modification does not modify the function key in the address at the same time
Response Metrics: successfully modified and updated
(3) Performance (Performance)
Performance is the ability of the system response time ---- i.e. respond to external stimuli (events) required or the number of events within a certain time processing.
Factors that affect performance: the amount and source of events to reach the mode. Usually with waiting time, processing time limit, the system throughput, response jitter (waiting time change), unprocessed events (can not respond because the system is too busy), loss of data system performance (due to the system is too busy) and other indicators to understand.
To Taobao, for example:
Scene: Users pay
Stimulus: User
Irritation: payment transactions
Products: user interface payment
Environment: User interface
Response: pay for success, success is returned
Response Metrics: to complete the transaction within two seconds
(4) Security (Security)
Security is a measure of the system in case of providing services to legal users, the ability to prevent unauthorized use.
There are three ways to attack: an unauthorized attempt to access data or services. Unauthorized attempts to modify data. Trying to use the system denial of service provided to legitimate users.
To Taobao, for example:
Scene: get product data changes
Source of irritation: non-authorized users
Irritation: trying to modify commodity prices
Products: System product data
Environment: The network firewall
Response: to authenticate users, prevent or allow access to product information
Response Metrics: data recovery
(5) testability (Testability)
Testability is pointed by the difficulty of testing disclosed software defects.
Can measure the response of the test process it is to test the efficiency of the discovery of defects in terms of coverage and want to achieve a desired, need to test how long.
To Taobao, for example:
Scene: Testing whether the system can complete the transaction
Stimulus: Testers
Irritation: Trading is normal
Products: complete applications
Environment: When you deploy
Response: You can complete the transaction
Response Metrics: to complete the transaction within two seconds
(6) ease of use (Usability)
Ease of use is concerned that the degree of difficulty to complete a desired task for the user.
To Taobao, for example:
Scene: the user to cancel the order
Stimulus: the end user
Irritation: get complete product information the user to complete the transaction
Products: Systems
Environment: Operating
Response: Order Cancellation
Response Metrics: Complete cancel the order within two seconds, remove the user's order history