SUMMARY
Cell migration is a central process which happens along with multicellular organisms' development and maintenance. The process that cells move to specidic locations in particular directions has some similarities with pedestrian walking behaviour. In this work, we propose a simulation model called an Intelligence Decision P System (IDPS), which is inspired by the process of cell migration. Each cell has its own decision-making mechanism and moving mechanism. They move towards its goals on a two-dimensional space under the guidance of external signals and its own regulations. Cells also communicate with each other according to specidic interaction mechanism. The environment is dedined as a place for cell movement. It includes signal objects, some of which help start or end the migration and others have great influence on the speed and directions of cells. It also keeps a record of current position for each cell. Comparing with traditional P systems, cells can be considered as intelligent particles with decision-making mechanism and they can move to their destination. A case study is about modeling and simulating a building evacuation problem in a dire emergency by using the IDPS model. To our best knowledge, the topic of evacuation simulation was not under study in the dield of membrane computing before. The simulation result shows that the IDPS allows much easier and more precise modelling of pedestrian evacuation problems. So it is supposed to be a good simulation model for pedestrian walking behaviour.