ANSI (1994) defines datums as any theoretically exact point, axis or a plane from which location and geometric characters of features of a part are established. Currently these datums are established using minimization of least square error technique resulting in an approximate estimation. This leads to production and acceptance of parts that deviate from the specification, hence affecting the functionality of the part. In this paper we present an algorithm for evaluating the datums of features of size under regardless of feature size (RFS) material condition. The non-linear optimization problem of datum evaluation has been reduced to a sequence of linear programs. An iterative procedure has been proposed to arrive at a local optimal solution starting with the least square value. As this procedure involves solving a sequence of linear programs, a faster, robust and near optimal solution is guaranteed. Examples and results are provided to illustrate the effectiveness of the procedure.
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