Soundness is the key property for evaluating "good" workflow nets
(WF-nets). In this paper, we examine several kinds of WF-nets with
well-known properties and prove that for these WF-nets, 1-soudness
implies soundness. Among these WF-nets, 1-soundness could be solved in
poynomial time for Free-choice WF-nets and Well-handled WF-nets, so
does the problem of soundness for them. Based on these results, we
introduced a special kind of WF-nets - WRI WF-nets which is inherently
sound and powerful enough for many modeling problems.