Abstract: In the production system,the critical equipment decides the production cycle and quality.In a sense,the critical equipment can be considered as the "bottleneck" of the whole production system.As a consequence,a certain production buffer should be set up to ensure the critical equipment working continuously.In this paper,in order to get an optimal result under the grey information,the authors firstly define and set up the "Grey Petri Net" and its algorithm applies.Secondy,a Petri Net analyzing model is set up to illust rate the principle of the buffer before the critical equipment.Thirdly,the authors establishe the buffer Petri net then simplify and solve it.Furthermore the authors apply genetic algorithm to get the optimal result.A tlast anexample is applied to show the feasibility and effectiveness of the method,getting a good result.

Key words: grey infor mation, critical equipment, production buffer, Petri net