Special features: computers have many uses, which can be used for a broad scientific, technical, and many areas of social life such as scientific computing, office automation, and economic management and so on (David Jin, 2011).

Reliability： computer has very high quality, therefore the reliability of it is very high.

Conformance: computer can match the prespecified standards accurately, so the conformance of computer is very high too.

Durability: the useful life of computer is about six years, so the durability of computer is just ordinary.

Serviceability: computer can be used in a lot of areas easily such as corporate governance, scientific calculation and so on, so it has high serviceability.