Abstract: Using stochastic Petri nets and triangular fuzzy parameters,this paper measures the fluctuation of the three stages of production cycle,and it conforms that the deviation of preceding production cycle leads to a greater deviation of the next production cycle.The fluctuation transfers from a stage to a subsequent stage in the whole production process,and it is amplified gradually.The phenomenon is similar to the bullwhip effect in supply chain.This paper provides a new way of thinking and method about measuring the fluctuation of production cycle caused by uncertainty factors.

Key words: stochastic Petri nets, lead time bullwhip effect, triangular fuzzy parameters