Material flow is shown on the plan of the factory as the routing of materials throughout the facility. It is important to show the status of the materials as well. This means indicating whether they are quarantined, approved or rejected, and also the volume, weight or frequency of movement, and the way in which the material is to be moved. Will it be moved by forklift truck, by pipeline or manually by people? Frequently people show all of this with different coloured lines on a factory layout with different thickness of line to show frequency of movement. In this way it is possible to identify areas of high movement frequency and where the floor is going to have to be very strong to resist the high workload that is placed on it. Materials should flow in the direction of manufacturing. There should be no cross-flow of materials. All of this information is placed on the factory layout plan.