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).
74
questions
2
votes
1answer
40 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 ...
2
votes
0answers
73 views
Production planning with production regularity over time
I've been studying a problem of the following kind:
$T = 1,\ldots, \max{T}$ is a discrete period of time, and we can use every production unit $i \in I$ at most twice. Every unit has a fixed attribute ...
6
votes
3answers
283 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
votes
2answers
58 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
votes
1answer
87 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 ...
2
votes
0answers
70 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
votes
0answers
44 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
votes
0answers
50 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 ...
6
votes
3answers
591 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
votes
2answers
100 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 ...
1
vote
1answer
74 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 ...
2
votes
1answer
83 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 company that ...
6
votes
1answer
237 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
votes
1answer
58 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 ...
4
votes
0answers
68 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
vote
2answers
86 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
votes
2answers
99 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 ...
5
votes
0answers
77 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 ...
-2
votes
1answer
168 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
votes
2answers
170 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
votes
1answer
103 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
votes
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 ...
0
votes
0answers
61 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
votes
1answer
95 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
votes
0answers
143 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
votes
2answers
130 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
votes
1answer
95 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
votes
1answer
117 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
vote
1answer
241 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
votes
1answer
129 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
votes
0answers
65 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
votes
2answers
389 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
votes
1answer
60 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 ...
3
votes
1answer
114 views
Space constraint in scheduling problem
I'm studying an MIP model with a scheduling problem and I'm wondering if the space constraint is correct.
If there is space in the factory at that time, the block can be processed, where
$i$ is the ...
3
votes
1answer
94 views
What kind of scheduling problem is this?
I am trying to develop algorithm to solve following basic version of the problem.
1) I would like to know what this problem is called in literature so that I can look it up
2) What are efficient ...
7
votes
1answer
1k views
How to use the least number of colours to colour different routes of a bus route such that no two intersecting routes will have the same colour
I would like to know of a method in which if provided say 10 routes with details regarding which route intersects with which another route, we can use the least number of colours to colour the routes, ...
3
votes
1answer
126 views
What type of scheduling problem is this?
I'm trying to develop a heuristic to solve a scheduling problem. The difficult for me is to treat the time as a variable.
There are 2 variables related to time, $b_{ij}$ and $f_{ij}$, being the time ...
2
votes
1answer
137 views
Nested set in OPL/CPLEX
I'm trying to solve a scheduling problem using OPL/CPLEX. In the model, there are nine tasks in which each task has its specific precedence. the precedence relationship is as follows:
...
4
votes
3answers
689 views
Job shop scheduling advice
I changed jobs recently to a manufacturing firm. Job shop scheduling is made 100% manually and intuitively in Excel. Very time consuming and they have no idea if the schedule made is something close ...
6
votes
2answers
116 views
Is this another variant of Job Shop Scheduling Problem?
The problem is as follows: there are $n$ jobs $\mathcal{J}=\{J_1,\ldots, J_n\}$, each of which could be done. There are $k$ machines $M_1,\ldots,M_k$ that work in parallel, independently of each other,...
6
votes
1answer
125 views
How to solve this variant of RCPSP
We have $m$ projects in parallel that require shared resources the resources has time varying capacities (i.e $B_{rt}$ is the units of resource $r$ available in period $t$). For each project there is $...
7
votes
3answers
378 views
Scheduling problem data generation
I compare the strengths and weaknesses of paradigms and approaches within those paradigms for solving machine scheduling problems. The amount of real-world data I have is limited and (random) ...
3
votes
1answer
112 views
Optimal way to ensure optional intervals are consecutive in OR-Tools
I am trying to solve a scheduling problem in OR-Tools. There are lots of "events" that need to be scheduled to "blocks" (essentially half-days). I am naturally using optional intervals for the events. ...
8
votes
1answer
109 views
Scheduling events in order to maximize preparation time
Problem statement
I'm given a set of events $E$, and $\forall e \in E$ also:
a set of plausible dates on which the event can happen $D_e$
importance (weight) $w_e$
ideal preparation time duration $...
9
votes
1answer
175 views
How to classify and model this problem?
I was given the task to model the following problem and find a solution for it, but as I do not have any experience in this field, I already have trouble classifying it.
There are a number of ...
6
votes
1answer
112 views
Optimal Energy Charging/discharging Scheduling Problem
I'm new to IBM CP optimizer.
I want to make charging / discharging scheduling based on cost (value will change on time) and my objective function is
$$\sum_{t=1}^{24}\sum_{j=1}^5x(1)^{(t,j)}x(2)^{(t,j)...
4
votes
1answer
152 views
How exactly does OptionalIntervalVar work in OR-Tools?
I created OptionalIntervals for a number of tasks:
...
11
votes
5answers
852 views
How to implement a “generic” solver for scheduling problems?
I have been accepted for an internship for 6 months. The aim of this internship is to implement a "generic" solver for scheduling/production planning problems. This solver will bill a small prototype ...
6
votes
0answers
76 views
Building the Scheurman's Model II constraints for a multi period linear program
Scheurman's paper discusses Model I and model II Formulation to solve harvesting and scheduling problems. It is a specific implementation to solve multi period linear programs. Both models are also ...
6
votes
0answers
116 views
Modelling issue with precedence constraint in OR-Tools
I'm trying to solve an RCPSPDc model It is infeasible, although Ilog Cplex solves it, so I think I have a modelling issue. I have more constraints but the precedence is the one that makes it ...
