Many researchers have identified the negative impact that
accounting methods have on reported profits as inventories
are being rapidly reduced. This research explores the magnitude
and duration of the negative impact on reported profits
experienced during a lean manufacturing implementation.
The effect on reported profit is evaluated under five accounting
methods (full absorption costing, activity-based costing,
direct costing, throughput costing, and order activity
costing) and three levels of inventory reduction rate.The findings
reported here indicate that the period-by-period gains
in operational efficiency, resulting from process improvements
brought by a lean program, will not counteract the negative
impact from the accounting system on the income statement
while inventories continue to be reduced. This could lead to
the early termination of a lean program that is, in fact, bringing
operational improvement in the present time, but the improvement
is being erased by poor inventory control practices
from past periods.