5 minute read
Complex logistics What is
Meike Reusken
Pieter Nijman
Logistics under the microscope
Every week, some 150,000 people can turn to one of the Dutch food banks. How can all the food distributed there be delivered to its destination in the most efficient way possible?
Text: Laura Bergshoef Photos: Bram Belloni
With his phone in his hand and folders under his arm, Pieter Nijman quickly walks into the cafeteria of the food bank and distribution center in Tilburg. “Sorry I’m late,” he says. “I just had to rescue a sea container full of mackerel. They were about to be destroyed, due to regulations, but the fish themselves are in fine condition. Isn’t that bizarre? I just put in a quick call. If it works out, every food bank customer will soon have a fish.”
Food waste and food shortage are important issues for Nijman. For some two and a half years, he has been a board member of the logistics department of the Association of Dutch Food Banks. In the Netherlands, more than one million people live below the poverty line. People who cannot afford groceries temporarily receive a supplemental food package once a week. How does that work? And what could be improved?
Bottlenecks
“The logistics behind the food banks is very complex,” Nijman says. The food banks get their food from such sources as businesses, supermarkets, and fundraisers. That food is first distributed to ten distribution centers. From there, it goes to 171 food banks, and most food banks have multiple distribution points. There, some 150,000 customers pick up a food package once a week.
“We want to distribute all the food, which is often fresh, as fairly as possible among various customers throughout the
Netherlands with as little waste as possible and as few kilometers to cover as possible,” says Nijman. “We never know exactly how much food we will be getting, and the number of clients per food bank varies over time.”
To clarify and optimize the logistics, Meike Reusken of the Zero Hunger Lab developed two mathematical models with master’s students last summer. “Big companies like supermarket chain Albert Heijn have a lot of data available. Mathematical models can make predictions using that data,” says Reusken. “Albert Heijn, for example, knows in advance each day how many people will come to shop at each location and what food they need to have ready on their shelves. I want to help the food bank with similar models.”
Reusken’s first model can predict the number of future customers, just like Albert Heijn’s model. “In the early 2020s, the food banks were worried that the number of customers was going to skyrocket because of the covid pandemic, but they had no idea how big the increase would be,” Reusken says. “That uncertainty made it impossible to prepare properly.”
The second model calculates the bottlenecks in logistics, including where there are insufficient means of transport and where means of transport could run more efficient routes. “What stood out, for example, was that food, nationwide, could be distributed more efficiently if the Food Bank increased the transit warehouses at certain distribution centers.”
The Tilburg Regional Distribution Center of Voedselbanken Nederland was recently renovated.
Twelve hundred loaves of bread
In Tilburg, Nijman walks down a steep flight of stairs into the distribution center’s gigantic warehouse. Towering metal shelving units are filled with cardboard boxes of all sizes. Volunteers in orange-and-black food bank fleece vests shout things at each other, others drive around in forklifts.
“This really is a gem,” Nijman says proudly. “The warehouse has just been renovated. We were running out of space.” Another board member, Will de Laat, nods affirmatively. “And the space is now more efficiently laid out as well.” He points to one of the shelving units in the front. “All this food has to go within a week, because this is all fresh.”
In one corner of the warehouse, a young man is concentrating on cutting fresh loaves of bread with a glistening slicing machine. “Twelve hundred a day,” says De Laat. A little further down, large doors are open. “That’s where the trucks load and unload; sometimes they’re up to 18 meters long. Here in Brabant, there are 29 food banks that come to collect food with their own means of transport.” But that number will be reduced. The model calculated that the number of kilometers could be reduced if the various food banks shared means of transport. So, instead of 29 separate trips, 5 trips will be made with different food banks as stops.
“I think that’s perhaps the best thing about the model,” Nijman says. “It allows the 171 individual food banks to work together better. Instead of asking what is most convenient for each individual food bank, the model looks at what works best for all of the Netherlands.” Reusken: “Consulting with 171 individual food banks is difficult. The model looks for possible regional collaborations from the top down.”
Mathematical tricks
Before Reusken got started with mathematics and computers, she first collected data about the food banks. “That was a huge job. The food banks don’t have as much data as, say, Albert Heijn. First, we prepared a survey with a hundred questions about logistics. Then I used that data to build the logistics model. This amounts to translating the data into mathematical formulas. The models then calculate how to optimize the logistics, for example, by reducing mileage as much as possible. The other model, which predicts how many customers the food banks will have in the future, uses mathematical tricks to find patterns in old data. Should there ever be another pandemic, the model now has data from the current pandemic, so we can prepare for the next one.”
In the warehouse in Tilburg, Nijman and De Laat walk through the door of the freezer. A crackling cold wind blows at them. De Late checks the room and grabs a stack of empty cardboard boxes. “I have to get going,” he calls after us as he quickly walks away. “I’m going to pick up food from a school.”
