When a limited number of specifications have to be met, this approach might work well. For testing programs where large numbers of specifications have be formulated, this approach can become intractable. Stocking e Swanson (1993)
introduced a Weighted Deviation Model, where targets were set for various specifications and the weighted deviation from these targets was minimized, and Luecht (1998) developed a Normalized Weighted Absolute Deviation Heuristic.