The concept of cutting tool life-cycle management was put forward, and divided it into four phases: planning period, input time, serviceable life and discarding period.
提出了刀具全生命周期管理的概念，将刀具全寿命周期管理划分为计划期、投入期、使用期、报废期四个阶段。
2
The four-period-life-cycle theory was once used by scholars to analyze the procedure of the management of the SARS crisis in China.