Documentation
Problem Types
Common categories of planning and scheduling problems.
SolverForge can solve a wide variety of planning and scheduling problems. Here are some common categories:
Scheduling Problems
Assign activities to time slots and resources.
Hospital Scheduling
Assign hospital staff to shifts based on:
- Skills and qualifications
- Availability and preferences
- Labor regulations (max hours, rest periods)
- Fairness (balanced workload)
Examples: Hospital nurse scheduling, ward coverage planning, specialty rota planning
School Timetabling
Assign lessons to timeslots and rooms:
- Teachers can only teach one class at a time
- Rooms have limited capacity
- Student groups shouldn’t have conflicts
- Preference for consecutive lessons
Examples: University course scheduling, school class scheduling
Meeting Scheduling
Find optimal times for meetings:
- Required attendees must be available
- Rooms must be available and large enough
- Minimize conflicts with other meetings
- Consider timezone differences
Job Shop Scheduling
Schedule jobs on machines:
- Operations must follow a specific order
- Machines can only do one job at a time
- Minimize total completion time (makespan)
Examples: Manufacturing scheduling, print shop scheduling
Routing Problems
Plan routes and sequences for vehicles or resources.
Vehicle Routing Problem (VRP)
Plan delivery or service routes:
- Vehicle capacity constraints
- Time windows for deliveries
- Minimize total travel distance/time
- Multiple depots possible
Variants:
- CVRP - Capacitated VRP
- VRPTW - VRP with Time Windows
- PDPTW - Pickup and Delivery with Time Windows
Examples: Delivery route planning, field service scheduling, waste collection
Traveling Salesman Problem (TSP)
Visit all locations exactly once with minimum travel:
- Single vehicle
- Return to starting point
- Minimize total distance
Examples: Sales territory planning, circuit board drilling
Assignment Problems
Assign entities to resources or positions.
Task Assignment
Assign tasks to workers or machines:
- Match skills/capabilities
- Balance workload
- Meet deadlines
- Minimize cost
Examples: Project team assignment, warehouse task allocation
Bin Packing
Pack items into containers:
- Items have sizes/weights
- Containers have capacity limits
- Minimize number of containers used
Examples: Truck loading, cloud server allocation, cutting stock
Resource Allocation
Allocate limited resources to competing demands:
- Budget allocation
- Equipment assignment
- Space allocation
Complex Planning Problems
Real-world problems often combine multiple problem types:
Field Service Scheduling
Combines:
- Routing - Travel between customer locations
- Scheduling - Time windows and appointment slots
- Assignment - Match technician skills to job requirements
Project Planning
Combines:
- Task scheduling - Activities with durations and dependencies
- Resource assignment - Assign people/equipment to tasks
- Constraint satisfaction - Deadlines, budgets, availability
Problem Characteristics
When modeling your problem, consider these characteristics:
| Characteristic | Description | Example |
|---|---|---|
| Hard constraints | Must be satisfied | Legal requirements |
| Soft constraints | Should be optimized | Customer preferences |
| Planning entities | What gets assigned | Lessons, visits, shifts |
| Planning variables | The assignments | Timeslot, room, vehicle |
| Problem facts | Fixed data | Employees, rooms, skills |
Choosing the Right Model
When modeling your problem:
- Identify entities - What things need to be assigned or scheduled?
- Identify variables - What values are you assigning?
- Identify constraints - What rules must be followed?
- Define the score - How do you measure solution quality?
The Getting Started section provides complete examples for common problem types.