Once you’ve completed the facility map, then identify and number all the pieces of equipment in the facility.10 Fundamentals of Preventive Maintenance This list will serve as the structure for tracking equipment maintenance activities. During this phase you will need to develop a numbering system for the orderly assign- ment of equipment numbers. Appendix 1 has a suggested generic numbering system that can serve as a starting point for your tailored system. You will accomplish this step by issuing workorders to gather data (e.g., S/N, model, size, manufacturer, age) on each piece of equip- ment in the newly mapped areas. With this data, you can then assign numbers to each piece of equipment.