A fully polynomial approximation scheme for the problem of scheduling n job
s on a single machine to minimize total weighted earliness and tardiness is
presented. A new technique is used to develop the scheme. The main feature
of this technique is that it recursively computes lower and upper bounds o
n the value of partial optimal solutions. Therefore, the scheme does not re
quire any prior knowledge of lower and upper bounds on the value of a compl
ete optimal solution. This distinguishes it from all the existing approxima
tion schemes.