his dissertation is mainly concerned with the problem of improvement at least normal Squares (ULS)  for  in the linear regression model  X  e, When the number of regression parameters is greater than or equal to two. Fact, For orthogonal data, the OLS estimate is consistently effective (obtaining estimates) With a minimum error box average (ms)). But in the presence of multicultural, and The efficiency of Operation Lifeline Sudan can be reduced and improvements are required desirable. Improved capacity is expected to be the smallest of small and micro enterprises By accepting some bias, these estimates can achieve a greater reduction in variability And a total reduction in micro and small enterprises...