Subject: linear programming software purchase
vince ,
i ' d like to purchase some copies of the xpress lp solver for the gas storage
optimization model . we have previously discussed the purchase of cplex , but
after trialing both systems , have found some worthwhile advantages with
xpress . if others find planner / cplex best suited to their application , i
see no problem is their use of a different system - both have strengths , and
it is likely that i would use planner / cplex myself on some future project if
we were to have both systems available .
xpress is particularly suited to my application because it handles special
ordered sets . this is a very efficient way of representing the storage
ratchets as the integer search process is able to use the extra information
provided by the set , rather than just using binary integer variables to
represent the ratchets .
planner is a c + + interface for cplex . it has some significant limitations ,
and does not permit access to all cplex features .
dash optimization have made the following offer :
all software purchases made by enron this year will be at 30 % off the list
price - we do not need to make a single purchase of any specific quantity of
licenses to obtain this discount .
90 days of full maintenance services will be provided with the purchase .
the emosl utility will be provided at no cost .
the xbsl system will be provided at no cost when it is released in a few
weeks time .
for the gas storage optimization model , i would like to purchase :
one development license , hyper version , with modeller , primal / dual simplex ,
mip search , dlls , emosl and xbsl when available .
list price $ 10 , 000 discounted price $ 7 , 000
two run time licenses for above ,
list price total $ 8 , 000 discounted price $ 5 , 600
total cost $ 12 , 600
i ' ve used the usually security request system to set the purchase process
going , should you agree to this .
tom .