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Aanand
AIMMSian
AanandAIMMSian
published in Sustainabilty & Social Good
Study 4Knowledge Base

Study 4: Create Multiple Plans for Resource Utilization This study can help you ensure resource requirements in your supply chain. Impact –Manufacturing plants and warehouses will experience a sudden shift in resource utilization. There will most likely be a reduction in labor hours as fewer people will work in a closed, crowded environments. This could even lead to total shutdown of certain plants. Action – Study multiple resource utilization what-if scenarios and accommodate your production plan accordingly.  How – S&OP Navigator allows users to simulate changes in resource capacity, labor hours, utilization, production lines and throughput rate dynamically within the application. The output is a detailed production and distribution plan that maximizes your margin. Note:If using your own bespoke app, another option is to re-adjust your objective function. We have seen this work very well in the past where a customer, during a crisis, moved from Production Maximization to Cost Min

8000
Aanand
AIMMSian
4 years ago
Aanand
AIMMSian
AanandAIMMSian
published in Sustainabilty & Social Good
Study 3Knowledge Base

Study 3: Identify Optimal Sourcing Locations This study can help you anticipate shortages in your supply chain. Impact – As transportation lanes become unavailable, the availability of suppliers and components will decrease.  Action – There is a strategic incentive in understanding the optimal sourcing location for specific customers, and in understanding the optimal sourcing location for the different resources. This is not to say that there is no value in having multiple supplier options, but understanding who your ideal supplier is can enable you to form the right relationship and expectations with them for the coming weeks.  How – Network Design Navigator enables forcing a single source as a constraint. Once the constraint is relaxed, customers are free to choose from a multitude of suppliers. However, with the constraint enforced, the optimal source of the product can be studied while minimizing both production and distribution costs. Network Design can also be used to make certai

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Aanand
AIMMSian
4 years ago
Aanand
AIMMSian
AanandAIMMSian
published in Sustainabilty & Social Good
Study 2Knowledge Base

Study 2: Inspect Demand Trends This study can help you understand exposure in your supply chain. Impact –Since demand will significantly fluctuate and spike for a period of time before reverting to the mean, accurate demand signaling for the future becomes a challenge. Misreading these signals often leads to the bullwhip effect. When shoppers decide to hoard all the toilet paper from the stores, it sends a signal through the supply chain to produce more. If the toilet paper companies decide to produce more, extra inventory is pushed into the distribution channel. Inevitably, demand will stabilize and when it happens, the stores will find themselves overstocked since customers are still exhausting their previous purchases. Action – Demand trends must be studied closely and any outliers must be treated to avoid inaccurate resource planning for the future.  How – AIMMS Demand Forecasting Navigator can be used to perform time-series analysis for individual product groups. Machine learning

8590
Aanand
AIMMSian
4 years ago
Aanand
AIMMSian
AanandAIMMSian
published in Sustainabilty & Social Good
Study 1Knowledge Base

Study 1: Anticipate Best- and Worst-Case Operations Scenarios This study can help you understand exposure in your supply chain. Impact – Prolonged shutdowns will have both financial and operation implications, which are often very difficult to realize due to the complexity and far-reaching nature of supply chains.  Action – Scenario planning is the key to understanding the many repercussions of sudden changes in demand and operations. Multiple best/worst case scenarios should be run under different demand conditions to study its impact on your supply chain. This can help expose any vulnerabilities in the network and take business a step closer towards preparedness.   How – AIMMS Network Design Navigator allows users to adjust demand for unique customers, locations and products. This means that you can target very specific parts of your demand data and dynamically run different scenarios in those conditions to measure its effect. On top of this, after demand has been adjusted, demand si

6960
Aanand
AIMMSian
4 years ago
Aanand
AIMMSian
AanandAIMMSian
published in Sustainabilty & Social Good
Immediate Supply Chain Actions to Take Amid COVID-19Knowledge Base

There are many impacts of COVID-19 that will be felt by Supply Chains in the coming weeks and months. As advised by McKinsey, in the next 2-4 weeks it is critical for companies to understand the exposure throughout their value chain, take actions to address anticipated shortages and ensure resources requirements to restart.   Supply chain planning tools like AIMMS SC Navigator can be used to directly address many of these impacts and help businesses recover quickly from losses.  We hope that this series of articles gives you some direction - and we welcome your comments and advice from experiences relating to these challenges.   Understand Exposure Study 1: Anticipate Best- and Worst-Case Operations Scenarios Study 2: Inspect Demand Trends   Anticipate Shortages Study 3: Identify Optimal Sourcing Locations   Ensure Resource Requirements Study 4: Create Multiple Plans for Resource Utilization Study 5: Refine Capacity Smoothing Study 6: Accelerate Adoption of Relevant Customer Channels  

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Aanand
AIMMSian
4 years ago
F
Farhan SururyEnthusiast
posted in Math, OR & Optimization Modeling
Ant-Colony Optimization

Dear All, I want to develop Routing Problem Model using Ant-Colony method, does AIMMS possible to generate the method? Are there any example that anyone could share..?   Thank you very much  

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F
4 years ago
chrdttchavan
chrdttchavanNewcomer
asked in Math, OR & Optimization Modeling
Optimization Solvers

Dear All, Looking for a list of solvers (LP/MIP/NLP/quadratic), applications and limitations. Thanks.

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chrdttchavan
4 years ago
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bkoiralaExplorer
posted in Math, OR & Optimization Modeling
Integrated Electricity, Hydrogen and Gas Markets Modelling in AIMMS

Integrated Electricity, Hydrogen and Gas Markets Model (I-ELGAS)   The future energy system will be increasingly integrated in order to absorb large fluctuations in intermittent renewables. Electricity, gas and hydrogen markets are interlinked via technologies such as water-electrolysis plants, natural gas reformers as well as natural gas and hydrogen-fired power plants. Analysis of the future interactions between energy supply and demand requires a market-based system allocation model which accounts for interactions between these markets and simultaneously represents the infrastructures in these markets. As the interactions between these markets will only increase in the future, an integrated assessment of these markets and systems is necessary. At TNO Energy Transition, AIMMS is used to model the integrated electricity, hydrogen and gas markets (I-ELGAS). The model analyzes future energy system while considering interactions and linkages between these markets.   I-ELGAS model schemat

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M
3 years ago
Jess Es
Jess EsGrand Master
published in Math, OR & Optimization Modeling
Polaris Optimization Systems: Empowering Decision-making in the Energy SectorInterview

We spoke with Russ Philbrick, founder of Polaris Optimization Systems, about optimization solutions for energy sector customers. Find out how the AIMMS-based engine PSO (Power System Optimizer) helps the power industry make the most of renewable energy.    Can you tell me a little about your background in the energy sector? I started working with Alstom back in 1999 and was responsible for the engines used to plan day-ahead unit commitment and reliability unit commitment. That project was very successful, and even today a number of power markets still run on AIMMS as the core engine, based on that work.   What led you to start Polaris?  In the mid-2000s, I was asked to support efforts to represent what Alstom was doing to support wind integration.  I began to understand that, because of the variability and uncertainty of wind and solar, integration into the power grid presented new planning and operational challenges. With wind and solar, it’s a new kind of uncertainty and variability

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Jess Es
4 years ago
P
pira1338Explorer
asked in Math, OR & Optimization Modeling
How to start solving with an initial solution

Hi,  I have an initial solution assigned to the two-dimensional variable x(i,j) .  How can I start solving the mathprogram using this initial solution? I did the following steps but I need details about the element parameter which is the second argument  in sendtosolversession?)   Thanks in advance read x from file “sol.txt”; myGMP := GMP::Instance::Generate(MyModel);  SolverSession :=GMP::Instance::CreateSolverSession(myGMP); GMP::Solution::SendToSolverSession(SolverSession, ???)    

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4 years ago
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Paul KoutstaalNewcomer
posted in Math, OR & Optimization Modeling
Electricity market modelling in AIMMS

The COMPETES electricity market model   At PBL, the Netherlands Environmental Assessment Agency, AIMMS is used to model the European electricity market. We use this model for outlooks of future electricity market developments and to analyse policy impacts such as the impact of CO2 taxes on electricity generation and prices. COMPETES is a power system optimization tool that seeks to minimize the total power system costs while accounting for the technical constraints of the generation units, transmission constraints between the countries and the generation capacity expansion for conventional technologies. The model covers 28 EU member states and some non-EU countries (i.e., Norway, Switzerland, and the Balkan countries), including a representation of the cross-border transmission network interconnecting these European countries. There are 11 types of fossil-fuel fired power plants as well as nuclear, geothermal, biomass, waste, hydro, wind and solar technologies; unit by unit generation

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Jess Es
4 years ago
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MelikeNewcomer
posted in Math, OR & Optimization Modeling
Precedence Tasks

Hello,I couldnt formulize the precedence relation above in my constraints. Could anyone help me with that? I tried to use the Activities for the tasks but didnt know how to use them with constraintsThanks in advanceMelike

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M
4 years ago
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tobiNewcomer
published in Math, OR & Optimization Modeling
Risk-sensitive planning support for forest enterprises: The YAFO model

[h3][img]https://uploads-eu-west-1.insided.com/aimms-en/attachment/3a5ee8d8-bc38-449b-92b5-cff518432fd1.png[/img][/h3][quote][h2][i]“YAFO is a planning-support tool for the development of management plans under uncertainty focusing on the forest enterprise level. Based on existing stand data, the software provides the calculation of management scenarios (felling plans) for single stands that are optimized with respect to financial considerations and ecological constraints. Under these constraints, YAFO predicts timber stocks, harvest amounts and financial returns for each simulation period.”[/i][/h2][i]Härtl, Fabian; Hahn, Andreas; Knoke, Thomas (2013): Risk-sensitive planning support for forest enterprises. The YAFO model. In: Computers and Electronics in Agriculture 94, S. 58–70. DOI: 10.1016/j.compag.2013.03.004[/i][/quote] Yafo was developed at the [url=http://waldinventur.wzw.tum.de/index.php?id=start&L=1]Institute of Forest Management[/url] (Technical University of Munich)

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Jess Es
4 years ago
M
MelikeNewcomer
asked in Math, OR & Optimization Modeling
Errors with operators

I tried to multiply a set to a variable in my constraint, which gave the error There is no operation defined for operator "*" with the arguments of data type numeric and data type set. I need to find a solution to avoid this multiplication but come to the same result. sum[j,Stationen*Zuordnung_AufgabenStationen(i,s)]-sum[i,Stationen*Zuordnung_AufgabenStationen(j,s)]<=0

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4 years ago
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peddy3009Newcomer
asked in Math, OR & Optimization Modeling
limit a sum

Hello, my model has the following constraint: s(i,j)*x(j)+sum((m,t_), MW(i,j,m,t_)*y(j,m,t_))+sum((k,t_),MWK(i,j,k,t_))+dM(i,j,t)-dP(i,j,t)=B(i,t) The index domain is: (i,j,t) I want the system to accumulate all MWK(i,j,k,t_) respectively all MW(i,j,m,t_)*y(j,m,t_) from t_0 until t_=t and then to add this solution to s(i,j)*x(j). Because t (periods) is already in the index domain I defined a second index t_ in the period set. Unfortunately the system sums up all MWK(i,j,k,t_) over all periods and add this in every t. So if there is a MWK(1,1,1,5)=1 then the system adds this also in t=0. Is there any possibility to determine that the sum should start at t_=0 and end in t_=t? Thanks in advance!

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P
5 years ago
A
AIMMS Partner
AnkitBhagatAIMMS Partner
asked in Math, OR & Optimization Modeling
Disable some of Constraints in Model through a user interface

Hi All, I want to create a user interface or page where i can control some of the constraints to toggle and run the model. e.g. Lets say we have 10 set of constraints and I want to run the model with 8 currently while rest 2 I want to disable for the run. This needs to be dynamic Is there any documentation available for the same or any example. Regards Ankit Bhagat

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mohansx
5 years ago
K
Katja
asked in Math, OR & Optimization Modeling
Delete a project

Hi, I am using AIMMS for my bachelorthesis. How can I delete a project from "projects"? Thankyou

1
Arthur
5 years ago
R
RachelNewcomer
asked in Math, OR & Optimization Modeling
Implementing a 4-4-5 monthly calendar

I would like to implement a modified monthly calendar, where rather than each month being a strict calendar month, I use the 4 week, 4 week, 5 week pattern. Has anyone used this previously, and if so do have any tips to share? Thanks Rachel

2
R
5 years ago
luiswilbert
luiswilbertEnthusiast
posted in Math, OR & Optimization Modeling
How machine learning and optimization can be applied to Omnichannel Retailing?

Today, the challenge for the companies is providing consistent, yet unique and contextual brand experiences across multiple customer-aware touchpoints, including brick and mortar, marketplaces, web, mobile and social. In response to these new customer preferences, the Omnichannel Strategy has been created to be a fully-integrated approach to coordinate different channels using just one strategy, marketing, price, database, assortment and goals. In this context, optimization models, commonly used for Network Design, Inventory and Fulfillment, may not be the best alternative. I would like to discuss some topics: [list=1] [*]What are the new business requirement for Omnichannel Retailing? [*]How machine learning, optimization and analytics can be applied to Omnichannel Retailing? [*]What are the biggest challenges for optimization? [/list] Thank you in advance

2
luiswilbert
5 years ago
J
JWandNewcomer
asked in Math, OR & Optimization Modeling
Save Upper and Lower Bounds from Baron

Dear Ladies and Gentleman, I use the solver Baron for a NLP and solve several problems with an if function in the Main Execution. After a specific time limit is exceeded, I want to save the Upper and Lower Bounds in a file or even better in a Parameter. Is this possible? Best regards, Jacqueline Wand

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Jess Es
5 years ago
Patrick
Administrator
PatrickAdministrator
posted in Math, OR & Optimization Modeling
StackExchange got an Operations Research corner

StackExchange got an Operations Research corner now. [url=https://or.stackexchange.com/]https://or.stackexchange.com/[/url]

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Patrick
Administrator
5 years ago
S
sadoflyNewcomer
posted in Math, OR & Optimization Modeling
Bilinear terms in equality constraints (non-convex MIQCP) xy=z?

Hi, I have a non convex MIQCP problem, where the non convexity is illustrated in bilinear constrains like : x+yz=u where x,y,z,u are continuous variables, a general form of this topic is modeling or approaching the constraint : "xy=z" neither gurobi or cplex can handle it. I m wondering, should i use a non linear solver (like Baron)or is there a way to linearize the problem or to approach differently with gurobi or cplex ? Thnaks for your answers.

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Marcel Hunting
AIMMSian
5 years ago
C
ChiboEnthusiast
posted in Math, OR & Optimization Modeling
Simple constraint makes the model infeasible

Dear Staff, I am experiencing a weird behaviour within one of my models implemented in AIMMS. I have a simple flow model. Among others, there are the following variables: F, continous variable X, continuous variable The variables do not have lower or upper bounds, so they are free. Then there are some flow balance constraints in the network (i.e. flow in equal to flow out). The model works very fine when only variable F is used. But when I add the following constraint: F = X then I get an infeasible solution. While if I add the constraint F

2
C
5 years ago
Jess Es
Jess EsGrand Master
published in Math, OR & Optimization Modeling
Integer and Linear Modeling TricksBlog

Here's a post sourced from the old Tech Blog that points you to some handy tricks for integer and linear modeling! Modeling problems with an (integer) linear program sometimes requires some experience to recognize certain structures in the problem description that can be formulated in a linear way. On the website of the [url=http://faculty.nps.edu/vitae/cgi-bin/vita.cgi]Naval Postgraduate School[/url], you can find the document [url=http://faculty.nps.edu/dell/docs/Brown_Dell_INFORMS_Transactions_on_Education_January2007.pdf]Formulating Integer Linear Programs: A Rogues’ Gallery[/url] that tries to demystify the art of formulating linear and integer linear programs. They do this by introducing formulettes, which consist of a verbal description and the constraints and variables that model this verbal description. The first simple example of a formulette they provide is the following: [i]For each unit of [b]X[sub]1[/sub][/b] , there must be at least 5 units of [b]X[sub]2[

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Jess Es
5 years ago
C
ChiboEnthusiast
asked in Math, OR & Optimization Modeling
Modelling question - if then constraint

Dear Staff, I would like your tips for an if-then constraint. In particular, I have the following variables: [b]R, binary variable[/b] [b]P, continuous variable[/b] [b]Y, continuous variable[/b] I have the following parameters: [b]A[/b] [b]B[/b] The constraints I would like to write are the following: 1) if R=1 then P = A*Y 2) if R=0 then P = B*Y I would like to know if it is possible to have a linear formulation without using indicator constraints. Thank you,

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C
5 years ago
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