The criteria for designing optimal pulses by using cost functionals is discussed. A wide range of cost functionals can be reduced to two basic functionals by introducing the product spaces. To solve the generalized pulse design equations derived from the basic functionals, monotonically convergent algorithms are extended. It is found that the new algorithms exhibit monotonic convergence. In four-level model systems, numerical test are implemented by employing stationary and/or nonstationary targets in the absence and/or presence of relaxation.