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).

Filter by
Sorted by
Tagged with
3
votes
1answer
75 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
66 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 ...
-4
votes
0answers
67 views

maximizing paid time off

A friend of mine is trying to optimize his use of paid time off using IP/BP and I thought maybe you would be able to help (see below). John Doe works only on business days and loves to travel in his ...
2
votes
0answers
41 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
46 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
votes
3answers
559 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
98 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
70 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
78 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
231 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
54 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
61 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
80 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
96 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
76 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
166 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
163 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
100 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
93 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
133 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
123 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
88 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
99 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
238 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
127 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
340 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
112 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
89 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
120 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
122 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
633 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
114 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
124 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 $...
6
votes
3answers
373 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
108 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
104 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
172 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
134 views

How exactly does OptionalIntervalVar work in OR-Tools?

I created OptionalIntervals for a number of tasks: ...
11
votes
5answers
806 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
114 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 ...
12
votes
1answer
330 views

Job Shop Scheduling: what objectives are harder?

It is well known that job shop scheduling problems are notoriously hard from a computational point of view. Many papers exist for the makespan objective, and some report on min sum objectives (like ...
12
votes
1answer
97 views

Improving cuts from sub-problem with problem-specific hierarchical information

I'm solving an assignment-alike problem with a Logic-based Benders decomposition-alike (LBBD) method. The master problem provides an assignment, which is checked in the sub-problem. Define the set of ...
7
votes
1answer
95 views

Variant of job shop scheduling problem

I'm looking to identify a problem in the literature that I'm currently solving. I have a set of jobs each having a set of operations. Each operation has a duration. An operation may be done by a ...