Networks engineered around the production line.

On a synchronised assembly line the network is part of production, not a service supporting it. Industrial Ethernet carrying motion and I/O traffic works to cycle times and jitter budgets far tighter than office networks require, so behaviour tolerated on a corporate estate, slow spanning-tree reconvergence or unmanaged multicast, arrives as a stopped line. Safety functions can run over the same media. EN ISO 13849-1 requires the safety-related parts of a control system to be designed to a required performance level and the level achieved to be verified against it, so changes touching those parts are not routine network work.

IEC 62443-3-2 requires the system under consideration to be divided into zones and conduits on the basis of a documented risk assessment, so segmentation follows process risk rather than network convenience. IATF 16949, applied alongside ISO 9001 by organisations supplying production parts, sets requirements for contingency planning and for traceability, which depends on data capture continuing while a switch is replaced. TISAX, operated by the ENX Association against the VDA ISA catalogue, provides a mechanism for exchanging information-security assessment results across the automotive supply chain, so a buyer should confirm the status of any organisation receiving prototype data.