Questions tagged [scheduling]

For questions about methods that assign resources to work requests (e.g. processor time to tasks) usually minimizing some cost measure (e.g. makespan).

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multiple cranes scheduling optimization [closed]

So i'm working on my school project and The problem is described as follow: we have 31 baths and 4 cranes '1 axis of movement'. figure 1: a crane imageimagen_2021-06-01_120450.png figure 2: baths ...
3
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1answer
48 views

How would I model the following problem concerning customer service via FCFS vs Appointment Scheduling

I'm unfamiliar with OR, and would like to get some advice on how to "think" about this scenario: I work for an organization that primarily has store fronts. Customer's arrive throughout the ...
2
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2answers
115 views

What kind of scheduling/packing problem is this?

I have the following problem which seems to be a mixture of a resource constrained scheduling and packing problem. There is a set of activities $A_1,\ldots,A_n$ and given precedences $P$, where $(A_i,...
4
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2answers
389 views

How to minimize the number of breaks in sports scheduling?

I have the following sports scheduling problem. For $n$ teams and $m$ rounds, I define the binary decision variable $$ x_{i,j,s} = \text{1 if team $i$ plays at home against team $j$ at round $s$, 0 ...
4
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1answer
305 views

Assignment and scheduling problem with resource constraints

I have 10 tasks with 6 workers. Each worker can only serve one task at a time and must complete the task before moving on to the next task. Each worker has a maximum work output value and each task ...
2
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2answers
80 views

Relationship aware task scheduling heuristics

I have a task scheduling/assignment on machines problem (like a classic bin packing problem) with a twist in which the placement/assignment of one task affects the placement/assignment of other tasks (...
2
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2answers
81 views

Modelling precedence relations

I have two tasks $i$ and $k$ with durations $d_i$ and $d_k$, where $d_i$ and $d_k$ are nonnegative variables. I would like to model that $i$ may precede $k$ or $k$ may precede $i$ and that they may ...
4
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2answers
151 views

Scheduling optimisation constraint on consecutive shifts & consecutive night shifts (`python`)

I am trying to write a program to schedule a team of 8 individuals into shifts. I want to know how to model that every individual must get at least one night shift break, and must not work two ...
2
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1answer
59 views

How does the RCPSP's precedence constraint work?

In [1] the authors define the RCPSP (resource-constrained project scheduling problem) as follows: minimize $$ \sum_{t} t x_{n t} $$ subject to $$ \begin{array}{c} \sum_{t} x_{j t}=1, \quad j \in J, \\ ...
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0answers
44 views

Modified bus scheduling problem question in ortools

Has been crossposted in stackoverflow. I want to solve the bus scheduling problem using ortools with some minor modifications. In my case, the max number of drivers is known. The modifications I would ...
6
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1answer
53 views

Real-life timetabling problems in education

I am looking for papers/resources that deal with timetabling problems in education. I want the resources to cover as much information as possible: I don't have enough contact with people who are ...
1
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1answer
74 views

Job Shop Scheduling Problem: jobs are scheduled on the same machine at the same time

I want to solve a job shop scheduling problem. I got $n$ Jobs that have to be scheduled on $k$ Machines. A Job $i$ has 2 or 3 Tasks $j$, and there is a known sequence of the Tasks of a Job. One ...
4
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3answers
126 views

Optimization formulation has slow performance

I am formulating and solving a scheduling problem. The problem consists of scheduling items on a single machine, where the only time element is the transition from item $i$ to item $j$. For example, ...
3
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1answer
47 views

How to assign task, resources to trips

In a scheduling problem I want to assign the resources to tasks, each task has earliest start date, latest start date and duration. Also each resource has fixed number of available hours in a day. The ...
2
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2answers
87 views

Scheduling: Tasks changing the state of the executing machine

I have a scheduling problem in which machines consume their battery when executing tasks and charge their battery when not executing tasks. A single task has to be executed in one go (no recharging ...
0
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1answer
46 views

What is a good approach to deciding which jobs (from a list of HPC jobs) should be ran locally vs. on the cloud given time & cost constraints?

Cloud computing has transformed the landscape of compute operations. Of course, there are still many labs/businesses with local, large-scale compute clusters. For those businesses who keep the ...
3
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0answers
51 views

Where I can study some job shop scheduling by course (video )?

I am seeking the help to know where I can study the job shop scheduling Heuristics or using solver by some course/video as I see some of books and papers hard to understand . It is hoped that the ...
3
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2answers
89 views

Scheduling Problem With Identical Machines

I am working on a nonlinear scheduling problem that minimizes the electricity cost of a facility. This system includes a number of identical machines that consume power and produce a product. When the ...
2
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1answer
53 views

MIP for resources to task assignments

I have few tasks t1, t2, t3, t4, t5 which need to be assigned to resources r1, r2, the tasks are located across multiple ...
5
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3answers
462 views

Gurobi and CPLEX cannot exploit more than 32 cores of machine

I have some attempts to solve a scheduling problem using the Gurobi and doCPLEX API in python and .NET on Ubuntu-server installed on a hyper-computing cluster with 64 physical cores. Unfortunately, ...
2
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2answers
63 views

Parallel scheduling with precedence constraints and variable job length

I have $N$ jobs and $M$ machines and want to minimize the makespan, i.e. the total time to finish all jobs. Some jobs have precedence constraints and can only be started once other jobs are finished. ...
3
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1answer
97 views

What are the flow based formulations?

What are the flow-based formulations? For what optimization problems are they applied, and in which form? Which are the specificities of such a formulation? Also, the same question for the time staged ...
3
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0answers
102 views

Production planning for a video game economy

I'm a software developer who likes to play a video game that has a complex economy. I realized that the type of problem I'm trying to solve mimics real life operations research problems, and I am ...
2
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0answers
47 views

Heuristic to compute upper bound for the simple assembly line balancing problem type 2?

I am currently working on SALBP-2 described as: Given the number m of assembly stations, minimize the cicle time c. I have done a bit of research and found the following approach to solve it: The ...
3
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0answers
52 views

Flexible Job Shop with Preemption

I'm trying to solve a flexible job shop problem variant that has precedence constraints on jobs along with a few other issues. We have a MIP formulation and also a simulated annealing algorithm to ...
5
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3answers
634 views

How to determine if this problem is NP-HARD or NP-COMPLETE?

Suppose that I have a pool with N nodes and I have to move the nodes one by one to another pool. For each move, consider a value on the edge linking the two pools. The goal is to find a order of nodes ...
3
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2answers
105 views

Relaxation and complexity of two formulations

I have two different MILP formulations for the same scheduling problem with the same complexity but with different running times. Why it is recommended to compare the relaxed versions of each ...
0
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1answer
88 views

What kind of job shop scheduling problem is this and how do I solve it?

I have a production planning / scheduling problem, which I believe is a kind of job shop scheduling problem. But I would like to get some input on what kind of job shop scheduling problem it is and ...
1
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1answer
107 views

Constraint programming and scheduling issues

I have a constraint problem that I need to resolve, but I did not how know to model the problem: I have 11 employees, I will name them from $a$ to $k$: $\{a,b,c,d,e,f,g,h,i,j,k\}$. I have a small ...
6
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1answer
241 views

Multi-period linear dynamic programming with differing in-period dependencies and changes

I’m not sure if I’m wording this right but in a nutshell, my problem is: I’m modelling potential actions a boat owner can do to their boat. Let’s say he wants to know over the 50 year lifespan of the ...
2
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1answer
71 views

MIP for assigning tasks with prerequisite tasks

I have a modified assignment problem for which I'm having difficulty formulating the constraints mathematically. I have a set of workers and a set of tasks which should be completed in the minimum ...
3
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0answers
79 views

Best known results on the flexible jobshop benchmarks

Is there a website that compiles the best known results on the flexible jobshop problem ? I know there was a blog post/article by Quintiq, a (deleted) blog post on CP Optimizer, some more recent ...
1
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2answers
91 views

How this problem can be defined as MultiObjective optimisation

I need to optimize the end-to-end latency of a multi-component application. Assuming that the application has 10 components, component 1-5 is hosted by device 1, and device 2 is hosting the other 5 ...
3
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2answers
101 views

How is this problem called in literature?

I have a scheduling problem but rather than having a fixed duration of each task, we have another "concept" that verifies the following property. Let's say task A requires a default 200 ...
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0answers
79 views

Quantifying Feasibility

I have a scheduling model formulation ( experimental setup) that takes in product states as input (sample points) and checks the model status (response) and returns feasible or infeasible. My plan is ...
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1answer
173 views

Optimized Production Planning & Scheduling

I want to create an optimized schedule and production to meet demand of four different buyers. I am starting with Pulp but not able to account for continuous production variable and discrete dispatch ...
2
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2answers
175 views

How to correct this scheduling algorithm?

I have a scheduling problem to solve. It's a resource-constrained project scheduling problem with time-varying resource availabilities. The objective is minimizing tardiness. The full detailed model ...
2
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1answer
108 views

Is a convex or MILP (without big-M) formulation possible for this problem

Assume we are given a directed acyclic graph (DAG) $G(V, A)$, where $|V| = n, |A| = m$, and the graph contains a source node $\mathbf{s}$ (i.e. every node in $V \backslash \mathbf{s}$ is connected by ...
2
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0answers
44 views

Scheduling with setup cost

I have a single worker that can work on N different tasks, but his total time T is limited. Let's assume time is in steps of 10 minutes (1 step = 1 mn). The payoff from a single job is 0 for the first ...
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0answers
63 views

How to identify an MVP for house building?

I am trying to find a minimal viable product for house building company. I don't know what are the commonly used constraints. Intuitively, I would say that: There is a set of tasks. Each task has a ...
3
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1answer
102 views

Can Deep RL be used to find optimal division point in an application?

I need to optimise the end-to-end latency for a multi-service application while distributing it on multiple devices. The application is a series of services interconnected to each other. The goal is ...
2
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0answers
151 views

Operation hours optimization for circular schedule

Here is my problem. A store has X = 15 electical devices with the ability to work non-stop, fully charged, up to 8 hours. Their battery charge lasts 2 hours and the operating hours of the store differ ...
3
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2answers
137 views

Limit number of switches in employee scheduling problem

Here is a scheduling problem I need to solve. Given the demand for 2 positions in 1 week with 3 shifts per position, I need to allocate the employees accordingly with some extra operational ...
6
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1answer
96 views

CVRP with vehicles blocking each other

I have a standard CVRPTW (capacitated vehicle routing problem with time windows). The instance is given by a (not complete) graph $G$ with weighted $w$ directed edges $e \in E$, and I have a limited ...
4
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1answer
149 views

Is it possible to solve VRP using OR-Tools CpModel, instead of RoutingModel?

Is it possible to solve VRP using OR-Tools CpModel, instead of RoutingModel? I want to do synchronized VRP, which is combining vehicle routing and scheduling constraints
1
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1answer
254 views

Can I apply decomposition methods for this scheduling problem

I have a centralized optimization problem for a residential area in the context of a smart grid and load flexibility. So let's say I have 10 buildings and each of them has an electric heating device. ...
3
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1answer
133 views

Resource constraint with MIP model

My question is how to model a resource constraint with MIP model (how should I modify it?) A factory is making blocks. If there is space left at that time, the block can be assembled. (If the factory ...
3
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0answers
68 views

Combining Machine learning and Operations research on a scheduling problem

I am wondering if there is any attempts of combining OR and ML in the following way. Priority-based rules are widely used in Resource Constrained Project Scheduling Problems. Is there a way to train ...
3
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2answers
547 views

How to add logical OR constraint in OR-Tools?

Let's say nurses normally do 1 shift for d in all_days: for s in all_shifts: model.Add(sum(shifts[(n, d, s)] for n in all_nurses) == 1) But I want to ...
4
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1answer
61 views

Business/industrial applications of the single machine scheduling problem

There is a lot of resources talking about the applications of scheduling in business in general. I would like to know about the applications of the particular case of single machine scheduling. Any ...