# 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).

198 questions
Filter by
Sorted by
Tagged with
2k views

### Best model for precedence constraints within scheduling problem

Suppose I'm modeling a problem where I want to compute the start time bucket for some jobs. All time buckets have equal duration. There are some additional constraints involved but I also have to ...
• 2,747
2k views

### How to model a mixed-integer linear programming formulation in Python using Gurobi?

I can remember that I spent some time in understanding how to formulate my first model. So I aimed at presenting a complete model here, wishing to save some time for students or researchers needing it....
• 2,104
1k views

### Number of aircraft to operate in an airline company

Suppose that an airline company has X planes, in general the companies keep a number of these aircraft (say 80% of X) in reserve in case of hazards. My question is how the airline companies compute ...
• 229
491 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 ...
• 5,909
173 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 ...
• 221
1k 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 ...
• 2,917
1k views

### Dealing with non-overlapping constraints

Let us consider the following problem: Let $T$ be a set of tasks. Each task $t \in T$ has a duration $d_t$ and a target start time $s_t$. No two tasks can be executed in parallel. The objective is to ...
• 2,398
1k views

### What is the difference between job shop scheduling and resource constrained project scheduling?

I read here https://slideplayer.com/slide/3353960/ that RCPS is a generalized version of job shop scheduling. I'm new to this area and I'm trying to classify a specific variation of these types of ...
380 views

### Algorithm for workforce scheduling for call volumes

I am trying to solve a workforce scheduling and optimization problem. Available data: daily level forecasted call volumes, shift schedules, resource utilization at the aggregate level, AHT at ...
674 views

### What is the state-of-art (in industry and academy) of this scheduling + routing problem?

I have a startup idea and I am coming from a CS background. The startup tries to solve the following problem. A company having a set of employees that needs to visit several "customers" each ...
• 309
251 views

• 1,414
447 views

### Finding minimum time for vehicle to reach to its destination

Given a set of Vehicles with source and destination I need to find the minimum time of travel for all the vehicles, there are also some charging stations and its necessary for vehicles to charge 1 ...
• 1,589
856 views

### What is this type of scheduling problem called?

I am currently working on software that deals with a specific type of scheduling problem, and I want to improve the scheduling algorithms that it uses. However, when I tried to research algorithms ...
• 196
247 views

### Workforce Scheduling problem - Modelling to minimize resources

I am working on a scheduling program for a service desk. I want to decide the number of people required to come in at each shift. The data I have is: There are 4 overlapping shifts Arrival pattern at ...
107 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 ...
• 567
198 views

### How to model 24 hours demand into a daily shift schedule?

I am working on a weekly staff scheduling optimization problem with 24/7 demand. The binary decision variable is: $X_{\text{staff},\,\text{day},\,\text{shift}}$ whether to assign the staff $s$ to day ...
233 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 ...
177 views

### Extract info from Gurobi binary variables during run-time

Actually the question below is not specific to Gurobi, but that's the tool I am using. Consider a scheduling problem where a 2D array of binary variables $Z(i,v)$ is defined, where $i$ is index of ...
• 281
168 views

### What class of scheduling problem models jobs which require multiple machines simultaneously?

In the Flow/Job Shop problems, and other related scheduling problems, a common assumption is that at any given time, a particular job will be being processed on at most one machine (usually... none). ...
• 636
101 views

### Examples for a kind of "set family hitting" problem

Given a ground set, say $[n]=\{1,2,\dots,n\}$, and a collection of subset families $\mathcal F_i\subseteq 2^{[n]}$, $i=1,2,\dots,m$, I want to select $m$ sets $B_i\in\mathcal F_i$ such that the ...
323 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 ...
• 2,224
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, ...
403 views

### Why most of constraint solvers do not support optional intervals?

Optional interval is a great idea of optional interval/task that can be active or inactive based on boolean variable. I found it very useful in complex scheduling problems. It was introduced in IBM Cp ...
• 189
284 views

### CPLEX CP Optimizer Java API function missing

I can not seem to find the needed functions to model the following problem through the Java API (CP Optimizer): a machine that has downtime and sequence-dependent setup times, with the extra ...
• 295
253 views

### What strategies to use for Scheduling of Connected Sequences?

I'm given a problem in which I need to schedule multiple sequences. The goal is to minimize the makespan. I'm allowed to elongate all tasks, but I cannot reduce their width nor disconnect any of the ...
• 73
1k views

### Finding an Objective Function for Assigning Employees to Sequence Dates

I am using a mixed-integer-program to schedule employees to projects. These projects can have a time window to get completed from a few weeks to a few months. At the moment I am working in a ...
• 1,193
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 ...