by the mid-1990s the advantages of the ems concept became compelling and oems began outsourcing pcb assembly (pcba) in large scale. by the end of the 1990s and early 2000s, many oems sold their assembly plants to ems aggressively vying for market share. a wave of consolidation followed as the more cash-flush firms were able to buy up quickly both existing plants as well as smaller ems companies.