The invention relates to a method of design of ruled surfaces. The method comprises the step of accessing data defining guiding curves P(u) and Q(v) and a cost function f(t, w). Given P(u) and Q(v), the unknown coupling is a parameterized curve s(t(s), w(s)). The method further comprises defining an objective function of the type J=J(f, t, w), involving both f(t, w) and coordinates t, w of the coupling curve. Then, optimizing the objective function J makes it possible to obtain the target coupling curve. Finally, a ruled surface S(s, λ)=Q(w(s))+(1−λ)P(t(s)) is provided, according to the guiding curves P(t(s)) and Q(w(s)), composed with the coordinates t, w of the coupling curve previously obtained. The objective function is further constrained at the optimization step such that arguments t, w of the cost function f(t, w) are regulated by a regulation function μ. The invention generalizes to any surface defined by guiding curves and further concerns a computerized system and a computer program product comprising means adapted for implementing the method of the invention.