Product lifecycle management (PLM) is software that keeps every version of each part of a product, and a record of who approved each change. A product such as a car or a tractor has thousands of parts, and each part is redesigned many times. PLM makes sure that everyone works on the right version.
Without PLM, drawings are kept in folders on many computers. Two teams can then work from two different versions of the same drawing, and the factory may build the wrong one. PLM keeps one approved version, and shows everyone which one it is.
PLM does not draw anything. The drawing is made in CAD. PLM stores the CAD files, the test results from simulation, the supplier details and the approvals, all in one place. It also keeps the bill of materials, which is the full list of parts that make up a product, with the quantity of each. PLM and an ERP system are different. PLM holds what the product is and how it was designed. ERP holds what to buy, what to make and what it costs.
Take, for example, a company in Hosur that makes electric scooters. An engineer decides that a footrest bracket should be 4 mm thick, not 3 mm. In PLM, she raises a change request. A strength engineer, a purchase manager and a production manager each review it, and each approval is recorded with a date. Then the bracket becomes version C. The bill of materials is updated, and the ERP system orders the thicker steel. The factory's manufacturing execution system (MES) builds only version C from then on. If a customer complains a year later, the company can see exactly which version was fitted, and who approved it.
PLM is used wherever the product is complex or must be traced. An aircraft maker keeps the full history of every part. Technical publications for aircraft, and aviation maintenance software, depend on knowing which version of a part is fitted on which aircraft. PLM also connects to should-cost analysis and to engineering data integration, which moves design data between tools. Fashion and building design use similar records, in 3D fashion design software and BIM software.
The record that follows a product from its design to its making, and then to its repair, is the digital thread. PLM is its main store. Companies rarely replace their PLM, because years of designs are kept in it.