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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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14 votes
4 answers
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....
Mostafa's user avatar
  • 2,104
7 votes
3 answers
329 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 ...
Clement's user avatar
  • 2,252
4 votes
1 answer
567 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 ...
conv3d's user avatar
  • 101
12 votes
2 answers
501 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 ...
Marco Lübbecke's user avatar
1 vote
2 answers
212 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,...
Daniel Binkele-Raible's user avatar
11 votes
5 answers
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 ...
Renaud M.'s user avatar
  • 2,418
11 votes
2 answers
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 ...
cdrootsudormstardashr's user avatar
8 votes
1 answer
169 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). ...
Brendan Hill's user avatar
8 votes
1 answer
448 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 ...
ooo's user avatar
  • 1,589
7 votes
2 answers
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 ...
Georgios's user avatar
  • 1,193
6 votes
3 answers
496 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) ...
Maarten's user avatar
  • 295
5 votes
1 answer
356 views

Scheduling with transition costs - DOCPLEX

I am dealing with a kind of scheduling problem. I have a set of tasks to be executed by a set of machines. It is known that different machines are able to execute the same task, but each machine can ...
campioni's user avatar
  • 1,133
3 votes
3 answers
267 views

Quantifying a measure of standard deviation in MILP

I am trying to set up a MILP for production scheduling. The specific details I'm not sure are important but in general a plant has M machines running N parts, each part requiring W workers. The model ...
Dano's user avatar
  • 55
3 votes
1 answer
200 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 ...
boroboro's user avatar
3 votes
1 answer
162 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 ...
boroboro's user avatar
2 votes
1 answer
460 views

CP-SAT solver doesn't use all space available for scheduling

This problem is a continuation of this problem. The issue here is the solver doesn't use the whole space available for the scheduling and thus some jobs are not being scheduled. For example: we need ...
Artem Popov's user avatar
2 votes
2 answers
394 views

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 ...
Ike348's user avatar
  • 343
2 votes
1 answer
147 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, \\ ...
NoThanks93330's user avatar
2 votes
1 answer
236 views

A specific case of a resource constrained project scheduling problem with partially renewable resources (RCPSP/$\pi$) - OR-Tools

I've been trying solve a specific case of the resource constrained project scheduling problem with partially renewable resources (RCPSP/$\pi$ in the literature e.g. this paper). These resources are ...
David Torres's user avatar
1 vote
3 answers
341 views

optimize days between work shift

For a work shift optimization problem, I've defined a binary variable in PuLP as follows: pulp.LpVariable.dicts('VAR', (range(D), range(N)), 0, 1, 'Binary') where ...
Jason's user avatar
  • 19
0 votes
1 answer
174 views

Rolling Horizon approach for solving a job scheduling problem

I am trying solve a scheduling problem adopting a rolling horizon approach. I have developed an Integer programming model and seek to speed up execution. I am seeking advice on beginner level ...
Pia MiA's user avatar
  • 392