The precision grade difference format that background function is \$x\+\{(0)\}(t)=b\%e\%\+\{-a(t+1)\}+c, in the basis of ideal absolute error, the gray Gompertz model, which is a new gray model is exlained and discussed.

Evaluating to software quality and testing process based on Gompertz model;

Then the Virene method and least square method are adopted respectively to estimate the parameters of the Gompertz model which is used to predict equipment’s future maintainability.

The settlement-time relation of foundation during the whole process of construction and operation can be described by a sigmoid or S-shaped curve,which can be modeled by the Logistic model and the Gompertz model.

The paper examines the algorithm by some instances and compares with the results of the Gompertz model.

By the theory and method of increase model,with statistical data in Fifty Years of Linan,the Gompertz increase model ^[KG-2][HT5”,5]y=6 exp [-5 802 0 e -0 367 9 t ] was established,which predicted the output value of forest products.