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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Reasonable implementation of a MILP scheduling problem
I have the following (fairly classical) "big-M" formulation of a scheduling problem. I am not able to solve it in reasonable amount of time for instances with more than 20 jobs (I am using ...
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Could I use numpy.arrays to represent the chromosome when solve Job scheduling in GA
I'm trying to solve a Job scheduling problem using a Rank-Based Encoding genetic algorithm that I envision encoding like this:
Represent the chromosome as an m x n matrix, each row of the array ...
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Is it possible to solve a classic VRP with 4000 node in 10sec by any powerful algorithms
I would like to solve a particular VRP problem encountered in industrial applications, where the model needs to plan the assignment of each customer point before performing path planning, and then ...
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How to model a sequential/consecutive scheduling?
I have the following scenario:
A factory needs to receive some amount of products from different sources $S$, in this case, from farms. The farms need to discharge all their product in the farm but ...
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How to request shifts when nurses _don't_ work
So I am working on a variation of the nurse scheduler.
This includes then the ability to have nurses request when they are going to be on...
However, I need to be able to support requests for when ...
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Need help for the python scheduling code
I'm working on a Python application using PuLP for optimization, and I'm having trouble ensuring that only one material is produced on a given day.
The constraint prob += pulp.lpSum(production_flag[m][...
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79
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Adopt constraint formulation
I have this constraint which ensures that there are at least $F$ consecutive days off. F.e. for $F=2$, an 1-0-1 is prevented.
$$1+y_{it}\ge y_{i(t-1)}+y_{ik}~\forall i\in I, t\in\left\{ 2,\ldots,T- {F}...
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Assigning resources to stations and tasks
I am new to operational research and using Gurobi for the following:
I am trying to create a task allocation problem. There are 4 types of resources Skilled and Unskilled workers and Normal and ...
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Improve a heuristic to solve the MS-RCPSP
I'm currently working on developing a heuristic to tackle the multi-skill resource constrained project scheduling problem (MS-RCPSP). I'd greatly appreciate any suggestions or modifications you may ...
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General convention for demand determination
I am currently writing my first paper and therefore relatively new to the Operation Research community. I have a physician scheduling model with novel demands and now I want to test it. Since the ...
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Scheduling categories of jobs with completion time requirements
Consider a discrete time slotted, system with two categories of jobs $J_1$ and $J_2$, where each job from the category $J_1$ has completion time requirement of $C_1$ and the jobs from category $J_2$ ...
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Schedule monotony constraints
Suppose I have a model for creating a nurse's duty roster. The model has the indices $i$ for the person, $t$ for the day and $s$ for the shift. I have the binary variable $x_{its}$ which indicates ...
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Is that an optimal solution for this instance of MS-RCPSP (Multi-Skilled Resource-Constrained Project Scheduling Problem)
I'm questioning whether this is the optimal solution for this instance of the MS-RCPSP (Multi-Skilled Resource-Constrained Project Scheduling Problem). I have checked the assignment and would like to ...
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Constraint formulation in MILP AGV Scheduling (using CPLEX)
I am currently working on a MILP formulation for optimizing AGV/AMR scheduling.
The model aims to optimize task scheduling across multiple missions using a limited set of resources. Parameters such as ...
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Issue with Mathematical Model Using PuLP Library
I'm working on a pulp python code for the MS-RCPSP (multi-skilled resource-constrained project scheduling problem), I need to update the code to address a specific scenario: when an activity requires ...
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Network formulation based side constraints for a workforce scheduling problem
For a workforce scheduling problem, I have formulated the "at most one shift per day" constraint as a network formulation based side constraint (with other constraints like demand coverage, ...
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Efficient Algorithm for Scheduling 140 Predefined 1:1 Meetings with Variable Participant Constraints Over 7 Slots?
I’m tasked with organizing a large number (130) 1:1 meetings for 50 people across a limited number of time slots (7) during a conference. I am seeking advice on the best algorithmic approach to tackle ...
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Complexity of average maximum completion time
There are $n$ jobs with different processing times, and they should be scheduled on $m$
identical machines such that the average (of all jobs, of all machines) maximum completion time (makespan) is ...
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multiple shifts per day constraint for a workforce scheduling problem
This is an extention to the workforce scheduling problem discussed in this thread Workforce scheduling problem. Adding a new post to discuss an important new requirement in this model. So the new ...
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Scheduling optimization problem - Where to begin?
Class Scheduling Optimization for a Trade School
We are exploring ways to model, simulate, and optimize class scheduling for a trade school, focusing on addressing the complex dynamics of managing ...
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Workforce scheduling problem difficulty
I am working on a workforce scheduling MIP -- given a set of shift candidates (different shapes and sizes of shifts created out of labor demand) and a set of workers, optimally assign the shifts under ...
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Problem 8.17 of Korte and Vygen
An airline wants to conduct a given set of scheduled flights with as few airplanes as possible. All
available airplanes are of the same type. For each flight we know the departure time and the flight
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Scheduling: Connecting the end and the beginning of the planning horizon
I would like to create a rota that repeats every 28 days and adheres to the usual rules. These include the minimum/maximum number of consecutive working days and the break days. I have created a model ...
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Execution time of sequential asynchronous process and division of labour
I wasn't sure if I should put this question here, but I guess is as good as any.
When we have a sequential process that has a number of tasks, were each task requires the previous one to be completed, ...
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Replace the constraint using ==> by a linear formulation
I would like to know how to express the continuity constraint without using a decision variable in the conditional form. My challenge is to stay with a linear formulation.
I will start to explain my ...
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Circular queue modeling
Let
$P$ be a set of discretely interruptible processes/tasks;
$T_i \in \mathbb{N}$ be the running time of process $i \in P$; And
$\tau \in \mathbb{N}$ be the maximum amount of time a process can use ...
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Implement a rolling horizon approach into a schedulig problem
I have just come across the topic of 'Rolling Horizon' in my literature research and would now like to apply it myself, but unfortunately I don't know where to start. This is my model, which is ...
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How to modify a model to be cyclic?
I have the following question. I have the following physician problem with the indices $I$ (doctor), $T$ (days) and $J$ (shifts). $x_{itj}$ is the decision variable, $d_{tj}$ is the demand and $g$ is ...
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How to model weekend constraints in a nurse rostering problem?
I have the following problem. I have a Nurse rostering problem and want to model the following. I have the indices $D$ (days), $I$ (nurse), $S$ (shift). My planning period $D$ is 28 days. Now I want ...
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Workforce scheduling optimization using ML model output
I am working on a workforce scheduling problem where we want to come up with an intelligent way to identify a set of shift candidates that is just enough to cover all labor demand but also flexible ...
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How to combine MIP solver with a CP one?
I am working on the scheduling problem in the class of parallel resource scheduling models. When I have studied some papers regarding that, I see the method that combines an MIP with a CP. The ...
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Job Scheduling with Energy Consumption using Linear Programming
I'm looking for some advice for an optimization problem regarding scheduling jobs in a datacenter.
So I have a list of jobs and each job has a required time for finishing and a number of cores it has ...
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Workforce scheduling problem
I am working on a employee scheduling problems (assigning shifts to temporary workers) by modeling it as a MIP. There is a one shift per day constraint for the employees. There are overnight shifts ...
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Compute time between tasks
I am trying to solve an optimization problem in which there is a set of tasks, $S$, where $s_i$ and $e_i$ are the starting and ending time of task $i \in S$. Each task $i $ must be done within its own ...
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Scheduling & Routing Problem
Looking for some advice on how to approach this combo scheduling + routing problem. I am a supply chain OR consultant, and was recently approached by a potential client. Without giving too much away, ...
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Pyomo + Gurobi Scheduling Tasks within Working Hours
I initially posted this on stackoverflow and got redirected here. You can view the old post with formatted tables here: StackOverflow Post
I have a python schedule optimization script using pyomo and ...
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The facet-defining inequalities for a single resource scheduling problem
Suppose, there exists a scheduling problem $S$, in this case a single resource, with the following descriptions:
$$ \text{conv(S)} = \{x \in \mathbb{R}^n \ | \ \forall \lambda_{i} \in \mathbb{R}^{n+}, ...
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Can dynamic programming find globally optimal solutions for scheduling problems
I want to know if dynamic programming can generally find globaly optimal solutions for scheduling problems? I think this might be difficult as dynamic makes one at a time decisions without calculating ...
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Mixed-Integer Programming Model for Scheduling with Dynamic Jobs
I have an optimization problem for deliveries between production lines and a warehouse in a small facility. I need to know how many vehicles and utilities to buy, such that cost and downtime are ...
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Is this classed as a version of jobshop? How should it be approached?
I'm looking at a problem that seems quite like flexible jobshop, but as I understand it jobshop is basically all about finding the order/sequence of tasks (across multiple machines potentially), ...
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How to define the sequence depending setup time based on a time index formulation
I am working on a scheduling problem in which I have used two different MIP formulations and also based on the time index variable. My problem is in the class $ P_{j} | \ r_{j}, SDST \ | C_{Max} $.
...
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Optimize cherry picking runs
I am trying to optimize a cherry picking procedure on 96-well microplates. The plates are 12X8 (12 columns, 8 rows). We pass a command file that has many lines like this to a robot:
...
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Formulation for choosing how many items to manufacture
I am working on a scheduler for a manufacturing plant. I have currently set it up so the decision variables are set up as binary variables:
$x_{m,p,s}$ = 1 if machine m is running part p on shift s
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Scheduling repeated tasks with minimum duty cycles
Several tasks need to run repeatedly in a channel, one at a time, over a repeating time frame of length $T$. Associated to each task $i$ is the duration $L_i$ the task will take to run, and a maximum ...
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In a routing and scheduling problem with break consideration, How can I determine whether a node is met before a break or after it?
I'm working on a routing and scheduling problem in the home care services context. I consider a break as a dummy patient, so routing and scheduling are also implemented for the break node (with some ...
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Linearization of Conditional Constraints for MIP using Cplex
I'm currently working on a mixed-integer programming (MIP) problem and I'm trying to implement a set of conditional constraints in CPlex. These constraints involve decision variables that are indexed ...
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Compute overlapping time
I am trying to solve an optimization problem in which there is a set of tasks, $S$, where $s_i$ and $e_i$ are the starting and ending time of task $i \in S$. Each task $i $ must be done within its ...
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How to fill the days in sequence?
I have a scheduling problem.
20 hours of work load should be assigned to different days (max 4 days are available and the capacity of ech day is 8 hours max)
$\sum_i h_i = 20$
$0 \leq h_i \leq 8$
The ...
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Scheduling to minimize total "wait to start" time
I have a scheduling problem I am trying to work through. As I was outlining the problem, I realized it is probably of a known problem type, but I am unsure of what keywords to search for or what ...
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