This paper deals with a comparative analysis of different pick & place strategies. The purpose is to give some rules to obtain a good sizing in terms of components (number of robots, conveyor speed) and control laws (individual scheduling rules of each robot, collaborative strategy of all the robots) of a multi-robot cell. This approach is validated by the use of a new simulation tool combining a behavioral simulation of multiple robots and the product flows. This simulation tool takes into account not only the end effector, but also the robots collaborative aspect to ensure the desired overall performance for a given task.