What is the Traveling Salesman Problem (TSP)? (2024)

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The traveling salesman problem is the problem of figuring out the shortest route for field service reps to take, given a list of specific destinations ensuring each location is visited exactly once before returning to the starting point.

Let’s understand the problem with an example.

A salesman wants to visit a few locations to sell goods. He knows the names of the areas and the distances between each one. What is the shortest route the salesman should follow so that he only visits each location once before returning to the starting point?

The TSP is an extension of the Hamiltonian Circuit Problem. It is one of the oldest and most studied combinatorial optimization problems and holds significant implications in complexity theory, including the P versus NP problem.

The vehicle routing problem and traveling purchaser problem are both generalizations of TSP.

The Background of the Traveling Salesman Problem

The traveling salesman problem (TSP) was formulated in the 1930s and is still extensively studied today. In 1972, Richard Karp proved that the Hamiltonian cycle problem is NP-complete, which led to the understanding that TSP is NP-hard—meaning the complexity of finding the optimal route increases factorially with additional destinations.

For example, there may be three possible routes for four cities, but there could be 360 possible routes for six cities.

This is because the brute-force approach requires evaluating every possible route and then selecting the best one.

This computational effort grows exponentially, making the problem infeasible for large numbers of cities using simple methods.

Despite these challenges, computer scientists have succeeded in calculating optimal solutions for thousands of cities since the early ’90s.

For instance, a large logistics provider could use such solutions to minimize the distance and time taken for deliveries within a state.

Why is the Traveling Salesman Problem Hard?

In theory, TSP can be solved by examining every round-trip route to find the shortest one.

However, as the number of cities increases, the number of possible routes grows rapidly.

For example, with ten cities, there can be over 300,000 round-trip combinations, and with 15 cities, this number exceeds 87 billion.

Early computer scientists hoped someone would develop an improved algorithm to solve TSP efficiently.

While significant progress has been made for specific instances, no universal algorithm can solve every traveling salesman problem case optimally within a reasonable time.

Hence, a one-size-fits-all solution might not be possible.

Applications of the Traveling Salesman Problem

TSP has broad applications across various fields. Solutions derived from TSP are used in:

  • Astronomy: To determine the shortest route a telescope should take to observe different stars.
  • Internet Planning: To optimize the configuration and data flow in networks.
  • Agriculture: For efficiently planning the harvesting sequences.
  • Microchip Production: To streamline manufacturing processes.
  • Computer-Generated Art: For creating intricate patterns with minimal paths.

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Challenges Faced by Traveling Salesmen

Modern salespeople face numerous challenges:

  • They often have unpredictable schedules with many confirmed and last-minute appointments.
  • Traffic congestion and specific delivery windows add to the complexity.
  • Balancing workloads and minimizing routes for a team of sales representatives becomes exponentially challenging.

With 100 customer addresses and eight salespeople, there could be more than a million possible route combinations. Evaluating each manually would take an impractical amount of time.

What is route optimization?

Route optimization is all about finding the most efficient route for a set of stops. Modern algorithms and tools help solve these problems more effectively than traditional methods like pen and paper or simple GPS apps.

ALSO READ: What is Route Optimization?

How to Solve the Traveling Salesman Problem with A Route Planner

As your team grows, manual route planning becomes too complex to manage using pen and paper or standard tools like Google Maps or Waze.

Without some heavy-duty tools like route planning software, you can not manually factor in things like roadblocks and weather conditions. As a result, you will end up spending a lot of time planning routes.

Unforeseen situations such as traffic congestion make it challenging to show up on time.

Balanced workload distribution is difficult if you try to optimize schedules manually.

You also risk increasing your operational costs. Often in the form of wasted fuel and salaries due to longer driving time.

Furthermore, your customers will be annoyed if your sales reps show up late or your drivers fail to make on-time deliveries.

ALSO READ: Why On-Time Delivery Is Important for Your Business

Vehicle routing software is the perfect traveling salesman problem solution.

A route planner powered by sophisticated algorithms like Dijkstra’s Algorithm reduces driving time and fuel consumption by finding near-optimal routes swiftly.

This helps tackle the TSP efficiently, ensuring on-time deliveries, cost savings, and enhanced driver safety.

 

Learn the six reasons why you need delivery management software.

Frequently Asked Questions (FAQs) about the Traveling Salesman Problem

What is the Traveling Salesman Problem (TSP)?

TSP is an algorithmic problem focused on finding the shortest possible route for a salesman to visit a set of cities exactly once and return to the starting point.

Why is TSP important in logistics and routing?

TSP helps in optimizing delivery routes, reducing travel distance, time, and fuel costs, thereby increasing efficiency and lowering operational expenses.

Can TSP be solved for large numbers of cities?

While it is computationally intensive to find the optimal route for large numbers of cities, heuristic and approximation algorithms can provide near-optimal solutions efficiently.

What industries benefit from TSP solutions?

Industries such as logistics, manufacturing, agriculture, and even fields like astronomy and computer-generated art benefit from TSP solutions.

How do modern tools solve TSP?

Modern tools use advanced algorithms and AI to quickly find efficient routes, handling multiple constraints like time windows and vehicle capacities, making them practical for real-world applications.

Conclusion about the Traveling Salesman Problem

Many real-world scenarios resemble TSP, with people and vehicles grappling with route optimization challenges.

While perfect solutions are difficult, advancements in complex algorithms and route optimization software have brought us closer to practical and efficient solutions.

The ongoing research and technology continue to improve how we approach and solve optimization issues in various industries.

Want To See For Yourself How Route4Me Can Boost Your Profits?

Whether you want to slash the time it takes you to plan routes for your drivers, increase the number of stops they can make, or keep your customers satisfied knowing that your drivers show up on time… Route4Me helps you achieve that!
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About author: Rahul Dasgupta

With a master’s in computer science and over two decades in logistics technology, Rahul Dasgupta is an authority in route optimization and last mile logistics. At Route4Me, Rahul uses his expertise to help businesses maximize delivery efficiency through strategic route planning and innovative logistics solutions, ensuring optimal fleet performance and cost-effectiveness.

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About Route4Me

Route4Me has over 40,000 customers globally. Route4Me's Android and iPhone mobile apps have been downloaded over 2 million times since 2009. Extremely easy-to-use, Route4Me's apps create optimized routes, synchronize routes to mobile devices, enable communication with drivers and customers, offer turn-by-turn directions, delivery confirmation, and more. Behind the scenes, Route4Me's operational optimization platform combines high-performance algorithms with data science, machine learning, and big data to plan, optimize, and analyze routes of almost any size in real-time.