Because they don’t support a multilevel hierarchical finished goods BoM.
The rate of MES system implementations in electronics manufacturing is not slowing. The rise of Industry 4.0 and the concept of big data have stimulated many companies to seek ways of collecting all important data in real time. If implemented properly, Industry 4.0 will eliminate the need for MES systems. Taking their place will be cyber-physical systems using machine-to-machine (M2M) communication and big data used to make intelligent decisions to run production without any human intervention.
There are still no signs, however, that we will come to terms with which M2M standard to use for Industry 4.0. Among Japanese machine vendors, an IPC-led effort, an ASM-led effort, and a Siemens-led effort, everyone else is left guessing what will happen and if an industry-wide standard will emerge at all. Until that happens, and until machine vendors implement better support for Industry 4.0, electronics manufacturers are pushing forward with MES implementations.