INVENTORY MODELS UNDER REMANUFACTURING YIELD LOSS
by
Z. Pelin Bayindir
University of Florida
One of the main sources of uncertainty in
remanufacturing applications is yield, since the state of the quality of returns
is not always sufficient for successful recovery. In this talk, two inventory
models under remanufacturing yield loss are focused on. In the first model, we
investigate the desired level of recovery under various inventory control
policies when the success of recovery is probabilistic. Returns depend on
demand; each item used returns to the system. All the returns go into a recovery
process that is modeled as a single stage operation. The recovery effort is
represented by the expected time spent for it. The effects of increasing
recovery effort on the success probability together with unit cost of the
operation are included by assuming general forms of dependencies. Alternative to
recovered items, demand is satisfied by brand-new ones supplied from an outside
vendor. Four inventory control policies that differ in timing of and information
used in purchasing decision are proposed. The objective is to find the recovery
level together with inventory control parameter that minimize long-run average
total cost. In the second model, we concentrate on the case where demand and
return processes are independent, and manufacturing is an alternative to satisfy
customer demand. Manufacturing and remanufacturing are performed in the same
facility, but there are dedicated resources for these two modes of production.
In this case, the probability that each return can successfully be
remanufactured is a parameter. We propose four different alternative
inventory-disposal rules that differ in information used to maximize long-run
average profit.
In this talk the models, the results of the computational studies together with
the managerial insights gained are presented.