#constraintprogramming #ortools #scheduling/#routing #optimization

I think I may have gotten this working in the toy problem. I can get a list of time-ordered optional intervals AND a circuit in the same order. That will let me put sequential constraints at the circuit level (I hope)

The key turned out to be to make sure all present intervals were also entered nodes AND that every x->y edge meant that x.time < y.time....and that the reverse is not true!

It's weird how confused I am by half-reified constraints, given that's *exactly* how programming languages do variable assignment.

a = b

makes a take the value b, but not vice versa.

#constraintprogramming #ortools #scheduling/#routing #optimization

I think I'm thinking about this wrong.

My basic problem is scheduling #radar collection intervals in continuous time. There are many constraints on the intervals already and that's all working (by which I mean "running"--I'm not actually connected to a radar yet).

However, I also want to put a constraint on interval *transitions* to make sure we don't require the dish to move instantaneously.

AFAIK, the only way to constrain adjacent items like this is via a circuit. So I was going to add a "circuit overlay" to the model. Then I could say that the "edge" from radar dwell A to radar dwell B had to be a certain time distance apart or whatever.

I'm writing a tiny test program to see how that works and it isn't doing what I expect.

But in debugging that, I think I just realized my entire plan doesn't work. There's no reason the circuit overlay is going to come out in the same order as the intervals as laid out in time. That voids the entire plan!

Also, even though all the kids are home for #christmas none of the #nerd are awake for rubber-duckying

GRRRRRRRRRRRRRR

#python #software #engineering

Finally getting back to the #constraintprogramming #ortools #scheduling/#routing #optimization problem

I have a minimal working implementation of both a server and a selection of agents at various levels of realism. Two other #software peeps are making two real agents to talk to my server

...and I'm realizing I need to bump up my game and get ahead of them...again

For most of the scheduling types/agents, routing is a non-issue. For a couple types/agents it is absolutely crucial. It's one of those that is being implemented by one of the #engineers. And if answers come back unrouted, a higher-level person is going to absolutely POUNCE and start advocating Bad Ideas

So I was looking into circuit constraints and there isn't a lot of info out there beyond the basics.

Until I found this wonderful tutorial

https://github.com/d-krupke/cpsat-primer?tab=readme-ov-file

It covers everything from the beginning to advanced and and even niche usage, including such important things as runtime parameters and timing. All in #python!

#thanksgiving

Automated Road Trip Planner | Integrating OR Tools, Traveling Salesman Problem, and OpenStreetMap

https://makertube.net/w/uXuhD6yakJ63AVFgc9VbfL

Решаем VRP-задачи, или Как мы в Додо доставку оптимизировали

Все сервисы доставки рано или поздно сталкиваются с аббревиатурой VRP. За ней скрывается сложная и важная задача оптимизации доставки. От того, насколько эффективно вы её решите, зависит и удовлетворённость клиентов, и реальные показатели бизнеса: скорость доставки, расходы на логистику. В этой статье я расскажу о типах VRP-задач, их отличиях, и о готовых решениях, которые вы можете затестить в ваших кейсах уже сейчас. Поделюсь подходами и инструментам, которые открыл в ходе исследования темы, опытом их использования и причинами, по которым я сразу отказался от некоторых из них.

https://habr.com/ru/companies/dododev/articles/904464/

#ORTools #Комбинаторная_оптимизация #VRP #Подбор_оптимального_маршрута #Алгоритмы #Транспорт #Курьерская_доставка #Логистика #Маршрутизация #Планирование_маршрутов

Permission granted: A role mining model

We implement a recently published role mining model using both constraint programming and mixed integer linear programming, then compare their relative performance while solving several examples.
https://www.solvermax.com/blog/permission-granted-a-role-mining-model
#orms #pyomo #ortools #python

Article: Well, that escalated quickly: OR-Tools

In this series of articles, we look at a simple optimization situation that requires deciding the best order for positioning devices in a rack.

This article discusses Model 4, which formulates the situation as a Constraint Programming problem and solves it using the CP-SAT solver in OR-Tools. Does it perform better than the previous methods?

https://www.solvermax.com/blog/well-that-escalated-quickly-or-tools
#Python #orms #optimization #modelling #ortools

If any #dotnet people have skills with Google #ortools #constriant-programming feel free to step in and point me in the right direction :-)

https://stackoverflow.com/questions/78489444/google-ortools-sat-cpsolver-solve-causes-accessviolationexception

Алгоритм генерации столбцов (Column Generation)

Генерация столбцов - подход к решению задач смешанного линейного программирования (MIP) с большим кол-вом переменных или столбцов. В статье представил теоретическую предпосылку, схему алгоритма и python реализацию подхода. В практической части рассмотрел решение двух задач: задача планирования расписания и задача раскроя.

https://habr.com/ru/articles/800527/

#column_generation #линейное_программирование #генерация_столбцов #математическая_оптимизация #задача_раскроя #задача_покрытия #ortools #задача_планирования_расписаний

Solving the knapsack problem with @ApacheGroovy
https://groovy.apache.org/blog/groovy-knapsack
#groovylang #optimization #chocosolver #knapsack #ortools

Many awesome projects and people underpin the optimization world. We're making mvs to surface more open source model code for real-world impact and better support individual decision modelers. @ryanjoneil explains: https://www.nextmv.io/blog/new-decision-apps-an-open-source-decision-model-hub-and-an-individual-plan

#orms #decisionscience #datascience #decisionops #pyomo #ortools

It’s that time of year: We’ve wrapped up our 2023 reflections, reviewed feedback and wishes for the future, and coalesced it all into our 2024 roadmap preview. Check out our next mvs: https://www.nextmv.io/blog/a-2023-look-back-and-2024-preview-of-whats-next-with-decisionops-and-decision-science

#orms #decisionops #decisionscience #informs #datascience #cicd #pyomo #ortools

Ortools — библиотека для решения задачи VRP

Привет! Меня зовут Илья Набатчиков, я MLE в компании Kamaz Digital. Также я являюсь учусь в онлайн магистратуре на базе университета ИТМО @ai-talent . Сегодня я хочу рассказать о библиотеке ortools для решения проблемы маршрутизации транспортных средств с учетом ограничений по времени и грузоподъемности (CVRPTW). И самое важно поделиться парой важных фичей, которых вы не найдете в документации.

https://habr.com/ru/articles/783754/

#ortools #комбинаторная_оптимизация #vrp

Планируем путешествие — задача коммивояжера (TSP) для построения оптимального маршрута

С вами Алексей Ложкинс, эксперт по анализу данных и машинному обучению в ПГК Диджитал. Мы разрабатываем цифровые продукты для логистической отрасли, в первую очередь, для ж/д перевозок. В кулуарах московского офиса ПГК мы обсуждаем и нерабочие темы. Топовую строчку в темах неформального общения занимает отпуск. Мы решили рассмотреть задачу планирования отпуска, как задачу оптимизации маршрута по выбранным достопримечательностям. Для этого воспользовались классической постановкой задачи коммивояжера. Моделирование маршрута в виде задачи коммивояжера позволит построить маршрут по всем запланированным локациям без повторений с заданным критерием качества (время, стоимость). Рассмотрим несколько подходов к решению оптимизационной задачи (TSP) с использованием пакета ORTools.

https://habr.com/ru/companies/pgk/articles/778782/

#задача_коммивояжера #ortools #целочисленное_программирование #tsp #линейное_программирование #точное_решение

“The application of OR-Tools and LAD regression for forecasting feels new, but the use of LP for shift scheduling is timeless.”

@ryanjoneil demos OR-Tools, HiGHS, Nextroute: https://nextmv.io/videos/forecast-schedule-route-3-starter-models-for-on-demand-logistics

#datascience #Python #logistics #lastmile #linearprogramming #orms #informs #ORTools

#MiniZinc 2.8 has been released. No big new language features, but it does include a lot of improvements to make your life easier:

- #ORTools is now part of the MiniZinc bundle.
- #HiGHS now provides intermediate solutions.
- Experimental support for propagator based meta-search, such as LNS variants.
- Commutative CSE
- Support optional version of global_cardinality, increasing, and count globals.

Find more details and many other improvements in the change log: https://www.minizinc.org/doc-2.8.0/en/changelog.html#v2.8.0

At @nextmv we like to do #optimization speed runs. In a couple weeks, we'll be upping the ante and do 3 in 30 minutes.

Come see the 3 main models you need to operate an #ondemand #lastmile service using 3 different solvers: #ORTools, #HiGHS and our own #nextroute.

https://www.nextmv.io/videos/forecast-schedule-route-3-starter-models-for-on-demand-logistics

🎉Our integration with Google OR-Tools is here – and we can’t wait for you to try it! Bring your OR-Tools model and launch it in minutes: https://www.nextmv.io/blog/the-nextmv-or-tools-integration-quickly-deploy-and-test-or-tools-models

✅ Deploy remotely to managed infrastructure
✅ Run acceptance and shadow tests
✅ Manage model versions (and partition data)
✅ Collaborate in a shared console space

Take it for a spin and let us know what you think 😀

#decisionops #orms #optimization #ortools #python #vrp #constraintprogramming #MIP #linearprogramming

Heyo #orms people, we’re making mvs! Go from 0 to 60 in seconds using google #ortools, #python, and @nextmv. Stay tuned for more updates Real Soon Now™️...

Blog: Warehouse optimization: Positioning and combining (Part 3 of 3)

In this article, we extend the analysis to answer our other two modelling questions. That is, can the efficiency of the picking process be further improved by:
- Positioning items according to order probability?
- Combining orders?
Overall we improve the efficiency of the picking process by 66% - a huge cost saving.
All the code is available, so if you think you can design a better warehouse layout, then please have a go. Let us know what you discover.

#Python #optimization #orms #ortools
https://www.solvermax.com/blog/warehouse-optimization-positioning-and-combining