The present invention relates to a method of constructing a variant of a parent Termamyl-like alpha-amylase, which variant has alpha-amylase activity and at least one altered property as compared to the parent alpha-amylase, comprising i) analyzing the structure of the parent Termamyl-like alpha-amylase to identify at least one amino acid residue or at least one structural part of the Termamyl-like alpha-amylase structure, which amino acid residue or structural part is believed to be of relevance for altering the property of the parent Termamyl-like alpha-amylase (as evaluated on the basis of structural or functional considerations), ii) constructing a Termamyl-like alpha-amylase variant, which as compared to the parent Termamyl-like alpha-amylase, has been modified in the amino acid residue or structural part identified in i) so as to alter the property, and iii) testing the resulting Termamyl-like alpha-amylase variant for the property in question.