A method including computing a multi-variable cost function, the multi-variable cost function representing a metric characterizing a degree of matching between a result when measuring a metrology target structure using a substrate measurement recipe and a behavior of a pattern of a functional device, the metric being a function of a plurality of design variables including a parameter of the metrology target structure, and adjusting the design variables and computing the cost function with the adjusted design variables, until a certain termination condition is satisfied.