# How can I save time solving my problem?

So I made a model at work that I need to solve and my problem is it takes way too long to complete. I use NEOS servers since I can only run bonmin on my computer and I am thus limited to 8 hrs. I tried using BARON and COUENNE. This is my model:

``````set P;
param C;
param scie;
param l{P};
param pond{P};																																	#fraction de pouce
var x{1..C} integer;
var LIEN{P, 1..C} binary;
var START{P,1..C} binary;
var y{1..C} binary;

maximize Prod: sum {p in P, c in 1..C} (LIEN[p, c]*x[c]*pond[p])* y[c];

subject to SumX: sum {c in 1..C} (x[c]+scie)*y[c]<= 96-scie;

subject to SumLIEN{p in P} : sum{c in 1..C} (LIEN[p, c] * (x[c]+scie))*y[c]<=l[p];

subject to x1{c in 1..C}: x[1]=0;

subject to x_min{c in 2..C}: x[c]>=4;

subject to x_max{c in 1..C}: x[c]<=20;

subject to emptysaw{i in P, j in 1..C}: LIEN[i,1]=0;

subject to start1{p in P,c in 2..C}: START[p,c]>=LIEN[p,c]-LIEN[p,c-1];

subject to start2{p in P}: sum{c in 1..C} START[p,c] <=1;
``````

This is a sample of 15 of my data. The real data is 120 long, but I could settle for 60:

``````param scie := 0.552;

param C:= 6;

set P :=
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
;

param l:=
1	3.948
2	13.448
3	17.448
4	21.448
5	25.448
6	29.448
7	33.448
8	37.448
9	41.448
10	45.448
11	49.448
12	53.448
13	57.448
14	61.448
15	66.448
;

param pond:=
1	0.0709
2	4.3669
3	13.5923
4	22.5757
5	21.1709
6	17.3977
7	10.9697
8	5.4999
9	2.6314
10	1.1629
11	0.3632
12	0.1159
13	0.0535
14	0.0159
15	0.0122
;
``````

Any help would be greatly appreciated!

Our new version of Gurobi for AMPL will solve this problem more efficiently – less than a minute for the data you give. Try solving with this data using Gurobi on NEOS, and if that doesn’t work, reply with the complete NEOS output from your run. (The version on NEOS might need to be updated.)

Thank you, I managed to run girobi on my computer and it is working a lot better than bonmin. Still took around 40 minutes tho. Maybe my pc is slow