Optimization Tooling

 I have large a planning problem in AIMMS, which is linear optimization. I am using GUROBI 9.0 for solving it and the solver is set to use the Barrier method based on our experience that Barrier converges faster than Simplex in our large-scale problem. After around 56 hours, the program stopped and I got the “Warning: Model status 13: Error no solution, solver status 1: Normal Completion”.Here are screenshots from the warning and progress panels of AIMMS.  Error/Warnings PanelProgress Panel​​​​​None of the existing questions and discussions on “Warning: Model status 13” are related to the case that it says “Solver status 1: Normal Completion”. I could not find any more information on software or the AIMMS manual regarding this issue. I need to find what is the source of this problem. I would be grateful if you can help me with this issue.Thanks,

hi all,sorry for the trivial question but was trying to figure out:how to force aimms to show “0” values for parameters and variables/results and correspondingly exporting those parameters to excel with “0”at the moment, whenever the parameter or variable has “0” is appears as empty line/cell.any hints on these two questions much appreciated!thanksnick

Good morning.I am converting our proyects in AIMMS from version 3 to version 4 and the DSN that already was used to connect to Access has failed. I used the extension (*.mdb), also tried with  (*.accdb) but doesn´t work. Could you help?Thanks a lot

I am trying to replicate the Softdrink Planning Tutorial, however it requires declaration of a  Compound Set. I have gone through the document:https://how-to.aimms.com/Articles/109/109-convert-compound-sets.htmlHowever, I am unclear how to convert the Compound Set given in tutorial. Could you please guide me through how to convert this particular set with set mapping. Thanks.  Set PlanningGanttChartRows {    SubsetOf : (Factories, ProductionLines);    Index : r;    Definition : {        { (f,p) | p in FactoryProductionLines(f) }    }}Set PlanningGanttChartBarTypes {    Index : b;    Definition : data { ’In Use’, ’In Maintenance’ };}ElementParameter PlanningGanttChartStartingWeek {    IndexDomain : w;    Range : Weeks;    Definition : w;}Parameter PlanningGanttChartDuration {    IndexDomain : (r,w,b);}

I am a beginner to AIMMS and was trying to create the Softdrink Planning model by following the procedures in AIMMS_tutorial_professional.pdf. However, I was stunk at specifying the table name attribute step in tutorial page 77/217. Whenever I click the “Table name” wizard, a window will pop up saying “Error opening datasource data\\Softdrink Planning.dsn make sure this is a valid datasource”. Anyone knows how to solve this issue? Your help would be highly appreciated!I also tried to click the “Table name” wizard in the completed project model but I still have same issue.

While calculating a Sum-Function  I encountered a problem  (see error message below):While using the power of X=1 and X=2 the model works perfectly however with any other number (also negative numbers) it displays the error below in red.Function: Sum[p, 2 * (L1(p)+0.001)^(X) ] Using +0.001 to avoid any division by 0 (in case of X being negative).L1(p) being a variable which is defined by a constraint L_1(p):Sum[i,L(p,i)] + L1(p-1)= L1(p)And L(p,i) in the constraint being a binary parameter. To run AOA the name of the AOA callback procedure should be assigned to suffix 'CallbackAOA' of 'Loesung'. For example: Loesung.CallbackAOA := 'OuterApprox::BasicAlgorithm'; where 'OuterApprox' is the prefix of the Outer Approximation module.Warning: Model status 13: Error no solution, Solver status 10: Error: Solver failure (see message window).Thank your for any help.  

I’m looking for help to extracting the first and last value of a given list. I have a binary parameter L(p,i) which will be given varios list of data.For example:List p=1: i=1 → 0i=2 → 1i=3 → 1i=4 → 0List p=2:i=1 → 1i=2 → 0i=3 → 1i=4 → 1I’m looking for a command which will extract the first i which is set to 1 on a given list. In this Example for the list p=1 it would be i=2 and for the list p=2 it would be i=1.I’m also looking for a command which will extract the last i which is set to 1 on a given list. In this example for the list p=1 it would be i=3 and for the list p=2 it would be i=4.I tried the “First” and “Last” command which always lead to using i=1 (for the command “First”) even though in the example p=1 the value of i=1 is 0 and not 1.Any help would be appreciated. 

I am getiing an error :The undeclared "1" is not an index. I am on the declaring identifiers portion of the course building my 1st AIMMS app.

I have a variable of a MIP problem, for example: total_power_plants = 2.7 but I only want to use the integer part of this value, that is 2, I have been reading this article but it does not work nor is it what we need (https://how-to.aimms.com/Articles/199/199-model-rounded-variable.html#example). Could you bring me some solution, please?

We have created a new AD group in our AD server. Added the AD group in Groups in AIMMS.However it seems like the changes in group members in Active Directory does not propagate in AIMMS group. We dragged the members to their new groups in able for them to be able to log in.Note that the Group name in AD and AIMMS group are exactly the same. Does AIMMS Pro have a back end process where synchronization between AD and AIMMS are set?Do we have sort of configuration that  sets the timing of synchronization? 

While solving a LP, I ran into the following error.  Below some snapshot from the message window.  100   9.7583200e+09   9.7583173e+09  3.89e+00  1.71e-01  1.34e-05  2.65e+03 101   9.7583195e+09   9.7583194e+09  5.20e+00  6.76e-03  6.16e-06  6.06e+04 102   9.7583195e+09   9.7583195e+09  1.78e+01  1.72e-04  2.39e-06  3.28e+06Barrier time = 767.38 sec. (945691.46 ticks)Parallel mode: deterministic, using up to 4 threads for concurrent optimization: * Starting dual Simplex on 1 thread... * Starting primal Simplex on 1 thread...Dual simplex solved model.Compressing row and column files.Advanced basis not built.Total crossover time = 300.28 sec. (132581.11 ticks)Total time on 4 threads = 1136.34 sec. (1101932.44 ticks)Memory in use by CPLEX 12.10.0.0: 8662892544 bytes.There is 8.26e+03 Mb in use by CPLEX 12.10.Warning: Model status 13: Error no solution, Solver status 10: Error: Solver failure.I am wondering if dual simplex solved the model, why there is error no solution?Any ideas to troub

A very basic question from a new user:I am trying to get started in the foundational training. When I create a new project to follow the basic tutorials, I am unable to create a new variable (though I can create sets and parameters). There is no error message that appears, but the buttons are grayed out (see screenshot below). I have tried in several AIMMS versions. Can anyone tell me what's going wrong here?

I want to write a function in AIMMS which should return a value or an element of Set X(say).The function is say F(a,b,x) where a in A, b in B, and x in X. The function F should return an element(or value) x1 from set X if x1 is in X otherwise returns no value.for Example, say F(a,b,x) = x - 10 and X = {x | 0<= x <= 100}F(a,b,20) should return 10  and F(a,b,8) returns no value or a default value which AIMMS will not consider when using this functions return value in a constraint.

I’m trying to see the nominal coefficients property for a variable. I have CoefficientRange property selected and my  Calculate Sensitivity Ranges is ON. However, it doesn’t show the property when the problem is solved with AIMMS Linear Presolve being OFF? Please advise. Here’s the documentation I found:.NominalCoefficient Definition: When the property CoefficientRange of a variable is set and the option Calculate Sensitivity Ranges is not set to off a coefficient range sensitivity analysis is conducted such that the optimal basis remains constant. As a result of this analysis the variable suffix .NominalCoefficient contains the nominal objective coefficient value.

Dear staff,I would like to receive some help writing the following constraint for a mathematical model.Within a graph, I define arcs (i-j) where “i” and “j” are nodes. For each arc and node, I also have the following variables and parameters:p(i) binary variablep(j) binary variablea(i,j) continuous variableC(i,j) parameterH(i) parameterH(j) parameterI would like to write a constraint expressing the following conditions:if p(i) = 1 and p(j) = 0, then a(i,j) <= C(i,j)*H(j)if p(i) = 0 and p(j) = 1, then a(i,j) <= C(i,j)*H(i)if p(i) = 0 and p(j) = 0, then  a(i,j) <= C(i,j) * (H(i) + H(j))/2if p(i) = 1 and p(j) = 1, then a(i,j) <= C(i,j)If you have any suggestions on how to write the above conditions within a constraint, I will be glad.Thank you,

Dear Community;According to our current Aimms project deployment practice, we deploy an end-user aimmspack file on Windows/Linux machines. The host Windows/Linux machines have a “normal” (normal means not Aimms-Pro) Aimms installed with an end-user licence. The projects are executed using Aimms.exe/AimmsCmd commands.However, we have recently developed a webui for a new project, we are now wondering if we must deploy using Aimms-Pro to have the webui working in the production environment? Can we install Aimms-Pro on Linux servers (I understand from the documentation that it is supported only on Windows servers)? If it is possible to access webui using “normal” Aimms (we prefer linux deployment):How can we define a static port for webui URL? We want to run aimms with --hidden flag and access the webui using a static URL. 

I studied the ‘’One hour beginner's course‘’ and tried the example. But there were something wrong with the number displaying. I can’t see the results in the table.(just as the second picture,there is blank in the table)

HiI am getting the following error while executing my code in AIMMS.ExcelSetActiveSheet(data.xlsx, Sheet1) unable to get a handle to the workbook: Could not open Excel.It would be grate if you can help me with this issue. 

hello,I was studying the tutorials provided by AIMMS and I came across a Production Model in the PDF Document for AIMMS for Professionals Tutorial. I’ve tried to open the file to see if it works but I come across the following errors as attached and it will not let me execute the model.  The zipped folder with the model has also been attached for your reference. Thank you for all the help!

Dear All,I’m writing to inquire about the application of uncertainty on a supply chain model. My Supply chain model has three echelons that target the production, warehousing, and distribution of medication products. The deterministic version of my model works perfectly, but is far from reality as production equals demand, which is why uncertainty of the demand parameter has to be considered.I was given a model (https://how-to.aimms.com/Articles/484/484-Uncertainty-productionplanningro.html) that briefly describes how to apply uncertainty to parameters, however, the given model was very small and didn’t help me in applying uncertainty to my desired project. As stated earlier, I have several medications to be sold in several pharmacies, therefore, the medication demand is not a single number but a matrix. I used the BOX function to define the demand matrix to be between a lower and upper pre-defined parameter matrices.The first problem occurred when I didn’t assign values to the uncerta

Is there any possibility to force the vehicles to drive on a specific route? Maybe using coordinates or stopovers?In my simulation my robots have to drive on a certain route to the customers and they have to minimize the space they move on out of the route.  

Hello,I haven’t finished my master's thesis because I need to install AIMMS in Amazon Web Services (to have a strong processing capacity, and I have US 10.000 credits). To do that I need to enter the Subnet of the university to activate the license through a virtual machine on Amazon (EC2). This has been impossible.Some help would be amazing or another solution.BP

As you may know, in the map widget, the end-user can scroll horizontally and vertically, by just grabbing a point on the map widget and dragging it to the desired position. Zoomed out, scrolling horizontally, you'll view the entire globe.This how to article shows a small application with a route sailing across the globe. A set of waypoints with legs make up a route for sailing across the globe. By scrolling horizontally, the route adapts dynamically to the visible part of the map widget.For instance, the app opens with the following map widget:After scrolling to the other side of the planet, the sailing route is shown as follows: 

Dear All,I have a question on how to limit the range of an index and since I’m new to Aimms I can’t find a proper solution. I just want to limit certain indices to a certain range for a specific constraint.First example (Constraint):Index Domain:tDefinition: e(t) <= e(t-1) |t<Tmax |t>TminError Message:In an inclusion only the middle term is allowed to contain variables, however in the inclusion e(t) <= e(t-1) $ t < Tmax $ t the left term contains variables. Second Example (Constraint):Index Domain: (i,j,k,t)Definition: r(i,j,k,t) <= o(i,k-1,t-1)*RM(i,j) |k>1|t>1Error Message: The operators <= and > should to be the same for numerical inclusion (or use parenthesis). As I’m new to aimms I dont seem to understand the principles properly. May someone point me to the right way to do this?Thank you very much in advance!Best RegardsJonas