# Tag Info

### Google-OR Tools: Assignment minimizing overlapping members

The MIP model by Erwin Kalvelagen is a good way to solve the problem, and is probably quite efficient. As an alternative, the following MiniZinc model is a fairly straight-forward model based on the ...
• 196

• 31.5k
Accepted

### Assignment Problem - Students and teachers

As in the comments: as it stands, the problem is infeasible. For student 3, they could never be given a class with any teacher, because they have never had at least two classes with any teacher. You ...
• 450
Accepted

### Google-OR Tools: Assignment minimizing overlapping members

It is often a good idea to split this task into two parts: Developing a mathematical model Implement the model (coding) Often, if you do a good job on (1), (2) becomes a breeze. Here is my attempt. ...
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### Optimizing Storage Allocation and Supply for Manufacturing with Time Constraints

I guess, as you correctly mentioned, this problem is too complex as actually many of the SCM problems are complex and I doubt one math formulation can handle all of its aspects. Instead, the problem ...
• 8,717

### Modeling: How to force customers visit their NEAREST facility

If you would like to assign the customers to the nearest facility, one way would be by adding a set-covering constraint to ensure the customers with the minimum distance from a facility are assigned ...
• 8,717
Accepted

### PuLP ensure first and last choice

Additional constraints $\sum_{k=1}^{t-1} x_{l,k} \le 1-x_{a,t} \quad \forall l \neq a$ $\sum_{k=t+1}^{T} x_{l,k} \le 1-x_{d,t} \quad \forall l \neq d$ where $x$ is the binary location pair variable ...
• 3,451
Accepted

### Effective methods for solving the assignment and packing problem

I don't think the following heuristic can be said to "guarantee near-optimal solutions", but it is quite straightforward to code and can make efficient use of parallel threading/multiple ...
• 38.8k
Accepted

### Assignment of colored boxes to groups

Here's a mixed integer linear programming formulation that I used to find an optimal solution with objective value $1506$ for your $10 \times 9$ instance. Let $(c_{ij})$ be the given (sparse) cost ...
• 31.5k
1 vote

### iterative geographic assignment problem

The urbanization part is easy. Fix $x_{vc}=0$ for all $(v,c)$ combinations that do not satisfy the urbanization constraint (either by adding an equation or simply by not including those variables in ...
• 38.8k
1 vote

### Google-OR Tools: Assignment minimizing overlapping members

The original data mises the team 9,16 (these two do not belong to any team) The code in OR-TOOLS Data ...
• 1,296
1 vote
Accepted

### Formulating assignment problem with people attributes that need to be balanced per assignment attribute in or-tools, CP-sat

You'd need two optimization variables Binary $x_{s,r} = 1$ if student $s$ from set A is matched with row $r$ from set B Binary $y_{s,c} = 1$ of student is matched to a class $c$ Derived sets/matrix ...
• 3,451
1 vote

### Modeling: How to force customers visit their NEAREST facility

Another way is for all customers $n$ sort the distance in ascending order into a set $S_n =\{d_{ni}: d_{n,i} \le d_{n,i+1}\}$ basically indexed by the facility. Then for each customer loop the below ...
• 3,451
1 vote
Accepted

### Assignment problem with multiple precedence constraints

The following assumes that the $(v,u)\in A$ precedence requirements have to do with the order cars are in a row and not something else (such as cars before trucks, heavy vehicles before light vehicles ...
• 38.8k
1 vote

### Is there a name for this variation of the generalized assignment problem?

The problem sounds like a parallel resource scheduling problem with preemption. One of the efficient way to solve the problem (as an LP) is to define that as a bipartite graph in which the first group ...
• 8,717
1 vote

### Is there a name for this variation of the generalized assignment problem?

It's similar to knapsack problem. I am referring to wiki links here from here you can refer to other additional academic papers. Also check this general wiki as well on general assignment problem. ...
• 3,451
1 vote

### PuLP ensure first and last choice

Here’s a somewhat automated way to obtain the formulation proposed by @Sutanu. You want to enforce the logical implication \bigwedge_t \left(x_{at} \implies \bigwedge_{l\not= a}\bigwedge_{k<t}\...
• 31.5k
1 vote

### PuLP ensure first and last choice

For anyone who comes across this in the future and is looking to translate the solution @Sutanu posted to PuLP, here is how I implemented it. ...
• 35
1 vote
Accepted

### Alternative Approaches to Assignment Problem

If you are open to heuristic (approximate) solutions, one possibility is to generate a set of routes and then rewrite the problem to assign trucks and customers/orders to routes. In problems of this ...
• 38.8k
1 vote

### Alternative Approaches to Assignment Problem

It seems that you are trying to solve a pickup and delivery problem. MIP solvers are often not the best tool for that, and getting good results with them requires special models and tricks. There are ...
• 1,867

Only top scored, non community-wiki answers of a minimum length are eligible