SUPPLY MANAGEMENT
Combined Part and Product Views for Sourcing
Optimization
The
cost model presented below was developed for projects C12-25, C13-25, and
C13-25 within the Center for Advanced Life Cycle Engineering (CALCE) at the
University of Maryland, College Park. The focus of the primary cost model is
the evaluation of the effect of two mitigating strategies, buffering and second
sourcing, associated with supplier specific disruptions.
Project C12-25
Background
In the C12-25 project a model was developed that incorporates the
evaluation of buffering and second sourcing strategies, defined in the key
terms section below, associated with sourcing parts. The resulting model is
capable of forecasting the number of parts in inventory, demanded, and
backordered. Using the forecasted parts counts, the penalty costs are assessed
and included within the cumulative cost of ownership of the part.
Project C13-25 Background
In the C13-25 project we extended the part-centric total cost of
ownership model (developed in project C12-25) to include:
1)
Product-level interface: An additional interface was added to the front
end of the model in order to collect and utilize product-specific inputs. The
following inputs in particular were divided by product: qualification/approval cost,
penalty cost, demand as a function of time, and product priority. The interface also allows the user to
decide whether or not to include specific products in the analysis.
2)
Solution management shell: A central ÒshellÓ was instituted into the
model in order to assess the effectiveness of multiple mitigation strategy
combinations. This shell allows for
the determination of an optimum management strategy.
Other minor additions and edits were incorporated into the model (such
as scrap costs and second-sourcing specific inputs) in the C13-25 project. User
reassessment of the optimal sourcing mitigation strategy is accomplished by
manually dividing the part-usage life into different assessment periods that
can then be run individually within the simulator.
Project
C14-25 Objective
The current model takes both the forecasted and
actual part demand (as a function of time) from multiple products and allows
for the determination of an optimal sourcing mitigation method. However, the
model lacks a generalized output needed to guide management-level sourcing
decisions. Starting with the model developed in projects C12-25 and C13-25 we
will perform the following work:
1) Incorporate the effect of inventory
aging into the inherent buffering model. Existing maintenance models need to be
explored in order to produce the most accurate cost calculations associated
with long-term inventory storage.
2) Explore the effect of human error
on sourcing disruptions. Human error falls under all of the major disruption
categories, however its cause is varied and its effect is difficult to predict.
Further research into human error modeling is needed, as it is one of the most
common causes of supply chain disruption.
3) Develop a novel framework within
the existing model that allows for the determination of the optimum disruption-mitigation
strategies associated with a set of inputs. Trends observed from the outputs of
sensitivity analyses performed in the part total cost of ownership model will
hopefully allow for a reduction in necessary inputs.
Key
Terms
á Second Sourcing: qualifying (and maintaining the
qualification of) an alternative part supplier (or source) to ensure a
redundancy in supply.
á Buffering: maintaining an inventory of parts equal to the
forecasted part demand of a fixed future time period.
Release Date |
Model & Documentation |
Version Notes |
Jan. 24, 2014 |
á
Software developed and tested with Microsoft
Office 2013 on Windows 8 platform. Compatibility with other operating systems
and programs is unknown |
|
Dec. 20, 2012 |
á
Software developed and tested with Microsoft
Office 2010 on Windows 8 platform. Compatibility with other operating systems
and programs is unknown |
Publications
V. Prabhakar and P. Sandborn, "A Part Total Cost of Ownership Model for Long
Life Cycle Electronic Systems," International Journal of Computer Integrated
Manufacturing, Vol. 25, Nos. 4-5, pp. 384-397, 2012.
For
questions, please contact hallison@calce.umd.edu
Center for
Advanced Life Cycle Engineering (CALCE)
University
of Maryland-College Park
Last
Edited: Jan. 23, 2014