After OEM strategic consolidation of transmission remanufacturing source, transmission remanufacturer in process of launching 5 production lines consecutively. As launch throughput failed to improve, customer backorders increased to significant levels. Plan to reduce backorders was high level and did not identify operational requirements and timelines. Solutions implemented by supplier did not appear to lead to sustainable improvements. Needed to identify root cause(s) and define action plan to reduce, then eliminate backorders.