 The equipment suppliers provide drawings of the equipment, which are used by the engineering company's mechanical engineers, and drafters to make general arrangement drawings, which show how the pieces of equipment are located in relation to other equipment.Layout drawings show specific information about the equipment, electric motors powering the equipment and such things as auxiliary equipment (pumps, fans, air compressors), piping and buildings.The engineering company maintains an equipment list with major equipment, auxiliary equipment, motors, etc.