FSD$\text{'}$s operating income using lean accounting principles should be compared against If the total plant$-$level costs are slightly higher than the total value stream costs for both Mechanical Devices and Electronic Devices and the difference between the total value$-$stream costs and the total plant$-$level costs is very small, this would indicate that the main opportunity for improving efficiency to reduce costs and improve profitability is reducing Value$-$stream operating income analyses allocated corporate overhead costs because these costs be controlled or influenced by plant$-$level managers.