“Gleaners” can help solve hunger, food waste and nutritional deficiencies, if volunteers managed efficiently – Deishin Lee

MIT Sloan Visiting Asst. Prof. Deishin Lee

From the Griffin Report, July, 2017

Food banks have benefited greatly from the incredible generosity of farmers and volunteers who have taken the time and made the effort of gathering produce left in the fields after a main harvest.

Indeed, the practice of “gleaning” which dates back to ancient times, has been growing in recent years as more efforts and associations are organized to meet the simultaneous need of feeding food-insecure persons at food banks and reducing food waste.

Modern-day gleaning in America is a noble endeavor, but is fraught with operational challenges that introduce inefficiencies into the process.

My colleagues Baris Ata, Xiaoli Fan, Miguel Gomez and Erkut Sonmez and I study the root cause of these process inefficiencies and how to address them in a series of papers, based on our work with the Food Bank of the Southern Tier in New York and the Boston Area Gleaners.

We found that a key part of the problem – and ultimately its solution – is tied to how volunteer staff members are utilized in the gleaning process. It’s not necessarily about a lack of volunteers. In its simplest terms, it’s about when and where those volunteers are deployed for gleaning operations.

But before we get into our recent findings on staffing and other key issues, let’s first step back to look at the larger picture of the gleaning activity itself and the challenges it faces.

It’s been estimated that about 6 percent of planted acres go unharvested in the U.S. To be clear: these are edible crops fit for human consumption that will be left in the fields to be plowed under unless someone goes back to harvest, or glean, them.

Simultaneously, it’s been estimated that about 14 percent of U.S. households faces food insecurity. Food insecurity is not just about hunger. It’s also about people not getting the healthy, micronutrient-rich foods that we all need.

So a gleaning operation is ultimately addressing three societal problems: hunger, food waste, and nutritional deficiencies.

But gleaning is not your normal business, or even a nonprofit, operation. First, it’s obviously subject to weather conditions and patterns, affecting when, where and how many crops are harvested. Second, there’s the issue of being dependent on volunteers who are not always, on any given day or weekend, able to drop everything so they can glean at a local, or sometimes distant, farm once a farmer notifies a gleaning organization that his or her fields are ready for gleaning.

It may seem like gleaning is all about the logistics of finding and coordinating enough volunteers to get a specific job done. This is part of the story, but not the complete story.

What we’ve found – and explained in “Dynamic Staffing of Volunteer Gleaning Operations,” “Improving Food Bank Gleaning Operations: An Application in New York State” and “Combining Two Wrongs to Make Two Rights: Mitigating Food Insecurity and Food Waste Through Gleaning Operations” – is that the real trick is to balance the number of farm donations accepted with the number of volunteer gleaners requested.

Accepting too many donations may burn out our volunteer gleaners, but turning down donations leaves crops on the fields that could be productively used and may discourage farmers from donating in the future. More trips or more gleaners is not necessarily better. Neither is fewer trips or fewer gleaners. The key is balance – just the right number.

Achieving this balance is not trivial because we can’t control the timing or the quantity of crop donations or volunteer labor. However, by applying modeling and optimization techniques from industrial engineering and operations research to gleaning, we can account for the randomness in the crop donation arrivals and when volunteers will show up, and select the optimal schedule and staffing level that maximizes the amount of food gleaned. We’ve also developed an algorithm for finding the optimal dynamic staffing policy.

The bottom line: We show that dynamic adjustments to staffing levels based on system congestion can recover approximately 14 percent of the produce volume lost using a static policy. The difference between scheduling too few or too many gleaning trips and just the right number of trips can make the difference of 10-15 percent or greater in total volume gleaned.

This is a step forward in terms of increasing the efficiencies of gleaning – and there are other future efficiencies to be found as gleaning organizations proliferate and grow in response to the increasing reliance on food security networks.

Again, there’s a lot at stake here: Reducing food insecurity and food waste. There’s plenty more work to be done. See you at the next gleaning!

Deishin Lee is a Visiting Assistant Professor at the MIT Sloan School of Management and Asst. Prof. at Boston College.

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