URC
Multi-Time
Period
Asphalt
Distribution
Model.
A
Multi-Time
Period
Asphalt
Distribution
Model
was
developed
for
the
United
Refining
Company
(URC).
Like
the
gasoline
distribution
model,
it was
designed
so that
individuals
with
no experience
in operations
research
could
use
the
model
to develop
seasonal
distribution
plans,
examine
the
manufacturing
process,
examine
the
time
value
and
cost
of inventories,
develop
appropriate
exchange
agreements,
examine
buy/sell
options,
and
several
other
options.
The
use
of the
model
results
in significant
reductions
in operating
costs.
The
system
models
shipments
of different
grades
of asphalt
from
refineries
to customers
over
a year.
In addition
to direct
shipments,
the
system
permits
more
complicated
shipping
procedures
including
exchange
contracts
(with
regrades
being
taken
into
account)
and
restrictions
on shipments
of groups
of products
within
single
shipments.
An important
part
of the
model
is a
front-end
manufacturing
model
that
permits
a quick
analysis
of the
manufacturing
options.
Among
several
other
features,
the
model
also
allows
the
analysis
of buy/sell
options
and
the
options
of incremental
sales.
An
accessible,
menu-driven
user
interface
permits
easy
modification
of the
components
in the
model
without
requiring
any
knowledge
about
the
associated
optimization
problem.
The
model
to be
solved
is typically
a mixed
integer
program.
It is
solved
using
a version
of MINOS
modified
to include
a branch
and
bound
integer
programming
algorithm
in addition
to the
linear
and
nonlinear
programming
procedures
it already
contains.
Output
appears
in terms
of the
data
components
familiar
to the
user
instead
of variables
from
an optimization
problem,
so interpretation
of the
model’s
results
is as
easy
as specifying
its
characteristics.
|
