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Coco - A full production planning example Description The Coco productional planning problem: multi-item,
multi-period, multi-site production planning. A sequence
of model versions show how the model
was developed, to (a) use more sophisticated modeling features
and (b) to extend the model, taking it from a simple linear model
to one with fixed prices and logical decisions.
Source Files By clicking on a file name, a preview is opened at the bottom of this page.
Data Files xbcoco.java
/********************************************************
* Xpress-BCL Java Example Problems
* ================================
*
* file xbcoco.java
* ````````````````
* Complete Coco Problem.
* Specify phase by PHASE parameter.
* Data input in the model, not via data files.
*
* (c) 2008-2024 Fair Isaac Corporation
* author: S.Heipcke, Jan. 2000, rev. Mar. 2011
********************************************************/
import com.dashoptimization.*;
public class xbcoco {
static final int PHASE = 5;
/* Phase = 3: Multi-period parameterised model; mines always open
* Phase = 4: Mines may open/closed freely; when closed save 20000 per month
* Phase = 5: Once closed always closed; larger saving */
static final int NP = 2; /* Number of products (p) */
static final int NF = 2; /* factories (f) */
static final int NR = 2; /* raw materials (r) */
static final int NT = 4; /* time periods (t) */
/****DATA****/
static final double[][] REV = {
{400, 380, 405, 350},
{410, 397, 412, 397}
};
/* Unit selling price of prod. p in period t */
static final double[][] CMAK = {
{150, 153},
{75, 68}
}; /* Unit cost to make product p at factory f */
static final double[][] CBUY = {
{100, 98, 97, 100},
{200, 195, 198, 200}
};
/* Unit cost to buy raw material r in period t */
static final double[] COPEN = {50000, 63000};
/* Fixed cost of factory f being open for one period */
static final double CPSTOCK = 2.0; /* Unit cost to store any product p */
static final double CRSTOCK = 1.0; /* Unit cost to store any raw material r */
static final double[][] REQ = {
{1.0, 0.5},
{1.3, 0.4}
}; /* Requirement by unit of prod. p for raw material r */
static final double[][] MXSELL = {
{650, 600, 500, 400},
{600, 500, 300, 250}
};
/* Max. amount of p that can be sold in period t */
static final double[] MXMAKE = {400, 500};
/* Max. amount factory f can make over all products */
static final double MXRSTOCK = 300;
/* Max. amount of r that can be stored each f and t */
static final double[][] PSTOCK0 = {
{50, 100},
{50, 50}
}; /* Initial product p stock level at factory f */
static final double[][] RSTOCK0 = {
{100, 150},
{50, 100}
}; /* Initial raw material r stock level at factory f*/
/***********************************************************************/
public static void main(String[] args) {
try (XPRBprob pb = new XPRBprob("Coco"); /* Initialize BCL and create a new problem */
XPRBexprContext context =
new XPRBexprContext() /* Release XPRBexpr instances at end of block. */) {
XPRBvar[][][] make, sell, pstock, buy, rstock;
XPRBvar[][] openm;
XPRBexpr lobj, lc;
int p, f, r, t;
/****VARIABLES****/
make = new XPRBvar[NP][NF][NT];
sell = new XPRBvar[NP][NF][NT];
pstock = new XPRBvar[NP][NF][NT + 1];
buy = new XPRBvar[NR][NF][NT];
rstock = new XPRBvar[NR][NF][NT + 1];
openm = new XPRBvar[NF][NT];
for (p = 0; p < NP; p++)
for (f = 0; f < NF; f++) {
for (t = 0; t < NT; t++) {
make[p][f][t] = pb.newVar("make_p" + (p + 1) + "_f" + (f + 1));
/* Amount of prod. p to make at factory f in period t */
sell[p][f][t] = pb.newVar("sell_p" + (p + 1) + "_f" + (f + 1));
/* Amount of prod. p sold from factory f in period t */
}
for (t = 0; t < NT + 1; t++)
pstock[p][f][t] = pb.newVar("pstock_p" + (p + 1) + "_f" + (f + 1));
/* Stock level of prod. p at factory f at start of period t */
}
for (r = 0; r < NR; r++)
for (f = 0; f < NF; f++) {
for (t = 0; t < NT; t++) buy[r][f][t] = pb.newVar("buy_r" + (r + 1) + "_f" + (f + 1));
/* Amount of raw material r bought for factory f in period t */
for (t = 0; t < NT + 1; t++)
rstock[r][f][t] = pb.newVar("rstock_r" + (r + 1) + "_f" + (f + 1));
/* Stock level of raw mat. r at factory f at start of per. t */
}
for (f = 0; f < NF; f++)
for (t = 0; t < NT; t++) openm[f][t] = pb.newVar("open_f" + (f + 1), XPRB.BV);
/* 1 if factory f is open in period t, else 0 */
/****OBJECTIVE****/
lobj = new XPRBexpr();
for (f = 0; f < NF; f++) {
/* Objective: maximize total profit */
for (p = 0; p < NP; p++) {
for (t = 0; t < NT; t++)
lobj.add(sell[p][f][t].mul(REV[p][t])).add(make[p][f][t].mul(-CMAK[p][f]));
for (t = 1; t < NT + 1; t++) lobj.add(pstock[p][f][t].mul(-CPSTOCK));
}
if (PHASE == 4) for (t = 0; t < NT; t++) lobj.add(openm[f][t].mul(20000 - COPEN[f]));
else if (PHASE == 5) for (t = 0; t < NT; t++) lobj.add(openm[f][t].mul(-COPEN[f]));
for (r = 0; r < NR; r++) {
for (t = 0; t < NT; t++) lobj.add(buy[r][f][t].mul(-CBUY[r][t]));
for (t = 1; t < NT + 1; t++) lobj.add(rstock[r][f][t].mul(-CRSTOCK));
}
}
pb.setObj(lobj); /* Set objective function */
/****CONSTRAINTS****/
for (p = 0; p < NP; p++) /* Product stock balance */
for (f = 0; f < NF; f++)
for (t = 0; t < NT; t++)
pb.newCtr(
"PBal",
pstock[p][f][t].add(make[p][f][t]).eql(sell[p][f][t].add(pstock[p][f][t + 1])));
for (r = 0; r < NR; r++) /* Raw material stock balance */
for (f = 0; f < NF; f++)
for (t = 0; t < NT; t++) {
lc = new XPRBexpr();
for (p = 0; p < NP; p++) lc.add(make[p][f][t].mul(REQ[p][r]));
pb.newCtr("RBal", rstock[r][f][t].add(buy[r][f][t]).eql(lc.add(rstock[r][f][t + 1])));
}
for (p = 0; p < NP; p++)
for (t = 0; t < NT; t++) {
/* Limit on the amount of product p to be sold */
lc = new XPRBexpr();
for (f = 0; f < NF; f++) lc.add(sell[p][f][t]);
pb.newCtr("MxSell", lc.lEql(MXSELL[p][t]));
}
for (f = 0; f < NF; f++)
for (t = 0; t < NT; t++) {
/* Capacity limit at factory f */
lc = new XPRBexpr();
for (p = 0; p < NP; p++) lc.add(make[p][f][t]);
pb.newCtr("MxMake", lc.lEql(openm[f][t].mul(MXMAKE[f])));
}
for (f = 0; f < NF; f++)
for (t = 1; t < NT + 1; t++) {
/* Raw material stock limit */
lc = new XPRBexpr();
for (r = 0; r < NR; r++) lc.add(rstock[r][f][t]);
pb.newCtr("MxRStock", lc.lEql(MXRSTOCK));
}
if (PHASE == 5)
for (f = 0; f < NF; f++)
for (t = 0; t < NT - 1; t++) /* Once closed, always closed */
pb.newCtr("Closed", openm[f][t + 1].lEql(openm[f][t]));
/****BOUNDS****/
for (p = 0; p < NP; p++)
for (f = 0; f < NF; f++) pstock[p][f][0].fix(PSTOCK0[p][f]); /* Initial product levels */
for (r = 0; r < NR; r++)
for (f = 0; f < NF; f++) rstock[r][f][0].fix(RSTOCK0[r][f]); /* Initial raw mat. levels */
if (PHASE <= 3) for (f = 0; f < NF; f++) for (t = 0; t < NT; t++) openm[f][t].fix(1);
/****SOLVING + OUTPUT****/
pb.setSense(XPRB.MAXIM); /* Choose the sense of the optimization */
pb.mipOptimize(""); /* Solve the MIP-problem */
System.out.println("Objective: " + pb.getObjVal()); /* Get objective value */
/* Uncomment to print out the solution values */
/* for(p=0;p<NP;p++)
for(f=0;f<NF;f++)
for(t=0;t<NT;t++)
System.out.print(make[p][f][t].getName() + ":" + make[p][f][t].getSol()
+ " " + sell[p][f][t].getName() +":" + sell[p][f][t].getSol());
System.out.println();
for(p=0;p<NP;p++)
for(f=0;f<NF;f++)
for(t=0;t<NT+1;t++)
System.out.print(pstock[p][f][t].getName() +":" + pstock[p][f][t].getSol() + " ");
System.out.println();
for(r=0;r<NR;r++)
for(f=0;f<NF;f++) {
for(t=0;t<NT;t++)
System.out.print(buy[r][f][t].getName() +":" + buy[r][f][t].getSol()
+ " ");
for(t=0;t<NT+1;t++)
System.out.print(rstock[r][f][t].getName() +":" + rstock[r][f][t].getSol()
+ " ");
}
for(f=0;f<NF;f++)
for(t=0;t<NT;t++)
System.out.print(openm[f][t].getName() +":" + openm[f][t].getSol() + " ");
System.out.println();
*/
}
}
}
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| © Copyright 2024 Fair Isaac Corporation. |
