Optimal designs for mixture models with amount constraints

Optimal designs for mixture experiments defined on the regular simplex are widely available but a lot fewer optimal designs are available for mixture experiments defined on the q-dimensional design space: S-*(q) = {(Z(1), . . . , Z(q))' is an element of R-q vertical bar Z(1) + . . . + Z(q) <= 1, Z(i) >= 0, i = 1, . . . , q}. This paper proposes a flexible class of models for mixture experiments defined on S-*(q) and gives a simple method for finding and A-optimal designs for the models using optimal designs available for the mixture experiments defined on the regular simplex. (C) 2012 Elsevier B.V. All rights reserved.