Rafael David Tordecilla Madera is a researcher receiving a grant at the UOC’s Internet Intedisdiplinary Institute (IN3), and an alumni of the doctoral programme in Network and Information Technologies of the UOC, jointly supervised by the Universidad de La Sabana in Colombia. He recently defended his thesis, which was graded excellent cum laude.
“This joint supervision agreement enabled me to do two doctoral degrees at the same time: the Doctoral degree in Logistics and Supply Chain Management at the Universidad de La Sabana and the doctoral programme in Network and Information Technologies at the UOC. And although I was part of different research groups, in the IN3 at the UOC, and the Logistics Systems group at the Universidad de La Sabana, I did only one thesis defence, and obtained both qualifications thanks to this agreement.”
Could you put your thesis into context for us? How does the problem come about?
The general theme of my thesis is transport and logistics. The most common problems in these fields are computationally complex – in other words, finding an optimal solution for this type of problem usually requires long computational times. That’s why we’ve designed a series of algorithms which can find a solution quickly, in minutes, seconds or even in real time.
When I began the thesis, my idea was to include uncertainty as an additional parameter in the modelling, as we needed a methodology that would ensure agility, flexibility and efficiency in solving transportation and logistics problems; that’s why I used heuristic, metaheuristic and simheuristic methods when I was writing it.
How does this research allow cost and time variables, which are essential for the transport and logistics sectors, to be optimized?
Our algorithms can generate different solutions in a very short time; they can generate a hundred or a thousand different solutions in a matter of milliseconds. Internally, the algorithm compares all these variables and chooses the best one depending on the company’s requirements. In other words, it can compare indicators in terms of costs, time, distance, etc., to provide the best solution, evaluating the different performance indicators at the same time. However, the solution will depend on the company’s requirements, which means that the algorithm can say that a specific solution is the best one in terms of cost, but if what the company wants is to maximize the use of lorries, for example, then another solution will be the best one.
There are developments focused on providing solutions to the transport and logistics sector. What distinctive contribution can this research make to these sectors?
One of the main contributions of my thesis is the ability to include different uncertainty parameters efficiently. To do this, we use fuzzy simheuristic algorithms, which means ones that use fuzzy logic, for variables that have fairly high uncertainty levels, such as customer demand, transport times on roads and in city streets, service times, which are the times taken to make a delivery at each client’s location, among others.
Can any company implement these algorithms? How can companies access this solution?
If the metaheuristic or heuristic algorithms that we design for a particular company are applied to another company, they won’t work if exactly the same ones are used, because the other company will have different characteristics, even when it works in the same sector. It will have its own particular characteristics, conditions and restrictions, and the information and input data won’t be the same. Nevertheless, because of their flexibility, the algorithms developed can act as a solid foundation that can be adapted and customized for application in other companies.
The thesis is also available in open access format. It’s based on scientific articles that have already been published, and which anyone can access either independently or via my entire thesis.
What made you choose the UOC?
I took the opportunity offered by the UOC to get a grant for doing my PhD, while also being part of the IN3. Otherwise, I would have had to pay, so the University’s offer of grants to researchers is a motivating factor. And although the grant was my initial motivation, I also chose the UOC when I found out about its academic level. The research group, with which I worked during these years, is a consolidated group, which has had a great deal of articles published and is widely known not only in Spain, but at the universities around the world with which it collaborates. That academic level is a great motivator, because you know that you’ll learn a lot if you join these research groups. And after more than three years, since I started working with the UOC, I can say that I have indeed learned a lot.
Can you tell us how you found out about the UOC?
When I was living in Bogotá, I signed up for a doctoral degree in logistics at the Universidad de La Sabana. At that time, Dr Jairo Montoya, the Director of the doctoral degree, told me about the call for doctoral grants offered by the UOC. That was when I found out about the University. I applied for one of the grants and, fortunately, I was one of the people selected. Although the UOC is a 100% online university, being a beneficiary of the grant meant I had to move to Barcelona, as I’d have an employment contract with the University.
The UOC has several doctoral grant holders – I’m not the only one. The University makes an economic effort when it rewards good researchers and gives them the opportunity to join any of the UOC’s research groups in order to contribute to producing different scientific articles. It not only enhances the University’s position, but also contributes to solving society’s real problems.