To solve the problem of performance appraisal of SME (Small and medium-sized enterprises) s' designers, this paper proposes a design method of appraisal system combining with product data management (PDM) workflow management. Designed a performance appraisal system model based on process management; taking into account the characteristics of supporting businesses, introduced a workflow template customization idea, and explains how it works. Designed data integrated interface the function module design with other functional modules; studied assessment algorithm of the system. The system is an effective solution to objective and automatic assessment of designers.