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lipury · ‎12-03-2020

Hi! Can you reverse the "from" and "to" fields in your input to proc. NETDRAW? Lindsey

lipury · ‎08-07-2018

This formulation uses the constraint solver with the ELEMENT and ALLDIFFERENT predicates to solve the original problem; the newer requirements haven't been addressed here, but it might be worth considering.

lipury · ‎01-03-2018

I've attached PROC OPTMODEL code that uses the REIFY and GCC constraints with the CLP solver.

lipury · ‎12-15-2017

Hi! The attached version incorporates the cardinality constraint of 35 apples per bag, which I had omitted. Unfortunately no solution is found with the new formulation after several minutes.

lipury · ‎12-14-2017

Hi! You might be interested to know that the CLP procedure implements a bin packing constraint, specifically designed to tackle problems like this one. The constraint programming engine can even be invoked from the OPTMODEL procedure using "solve with clp", but the attached code would need to be translated. I have made the assumption that the optimal solution is attainable. Alternately, one can add an objective function, but that formulation took longer to find an inferior solution. Thanks! Lindsey

lipury · ‎10-16-2017

Using "solve with CLP" with the OPTMODEL procedure, for all times t in [2,24], and for each pump p: 4 * p_(t-2) + 2 * p_(t-1) + p_t NE 2;

lipury · ‎06-14-2017

Hi! The first scenario can be addressed by introducing an activity "X" with the sole purpose of using up resource "LONDON" on day 2: proc clp schedtime=schedtime schedres=schedres; activity X = (dur=1 SGE=2 FLE=3); RESOURCE (LONDON); REQUIRES X = (LONDON); run; This scenario can also be handled by proc. CPM, using resource calendars, activity calendars, or the resource input data set to specify the resource level. The second scenario is what we have called a "REQUIRESSAME" constraint. Adding this constraint to CLP is a requirement that is under review for implementation in a future release. Thanks! Lindsey

lipury · ‎01-08-2016

I've included a couple more ways of obtaining the leaves from the proc BOM output below. The primary developer of BOM will return to work next week and might have some more suggestions. Thanks! Lindsey proc sql; select * from res where part_id not in (select distinct paren_id from res); quit; proc netdraw data=res out=ndout(where=(_X_ eq 1 and _SEQ_ eq 0)) nodisplay; actnet / activity=part_id successor=paren_id id=(_part_); run; proc print data=ndout; run;

lipury · ‎09-04-2014

Thanks for your question! We were wondering if you might be able to filter your part master data set with SQL prior to running the BOM procedure. BOM doesn't support wildcards or masking as far as I know. Regards, Lindsey SAS/OR Development

lipury · ‎07-18-2014

Hi! Thanks for the clarification. Unfortunately we don't currently see a way for the BOM procedure to automatically handle the by-product in the same BOM. The only thing we can suggest is to add a by-product flag (1 if a by-product or 0 if not) to the product structure data set, and use the RID= option to specify the new variable. Then, at least, you will be able to identify by-products in the indented BOM for post-processing. Regards, Lindsey

lipury · ‎07-16-2014

Hi! We weren't sure in your example if the C51 and C52 items are used to produce more of C5 or if the C5 by-product is used to produce C51 and C52. We do want to fully explore your requirement in the hope that we might be able to help. I spoke with the developer of the BOM procedure, and he thought that typically the by-products are produced in one BOM and consumed in another. You might introduce a multiplier variable (1 or -1) that could be carried into the output with the ID= option, to indicate whether the item is produced or consumed. Thanks! Lindsey

lipury · ‎07-16-2014

Hi! Thanks for your question. We are currently investigating this and will reply soon. Lindsey

lipury · ‎01-23-2014

I wonder if the CLP procedure might be applicable. This procedure includes a PACK constraint for placing weighted items in bins, subject to capacity constraints. Here is the documentation: SAS/OR(R) 13.1 User's Guide: Constraint Programming Thanks! Lindsey

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Re: PROC OPTMODEL for Nonlinear Integer Optimization - HELP!!!!

Re: Proc bom option to give the lowest level

Re: Multiple end items for proc bom

Re: How to reverse the ARROWHEADS in PROC NETDRAW procedure ???

Re: Proc OPTMODEL: finding optimal pairs - handling infeasibility

Re: Problem in formulating constraint

Re: PROC OPTMODEL for Nonlinear Integer Optimization - HELP!!!!

Re: PROC OPTMODEL for Nonlinear Integer Optimization - HELP!!!!

Re: Putting dynamical constraints on variables

Re: Resource Constraints using Proc CLP

Re: Proc bom option to give the lowest level

Re: Multiple end items for proc bom

Re: By-products in bill-of-materials (Proc BOM)

Re: By-products in bill-of-materials (Proc BOM)

Re: By-products in bill-of-materials (Proc BOM)

Re: Optimal binning