They adopted a trial-and-error procedure. 他们采取了一种反复试验的程序。
The method of explicit solution, avoiding a trial-and-error procedure and iterative calculations, provided excellent maneuverability of planning requirements, and it was convenient for oil field application. 但是,直接法不需要进行迭代计算,设计条件具有较好的可操作性,便于推广应用。