Ergonomics Practices In Manual Selection Operations

What Grocery Distribution Centers Are Currently Doing to Prevent Musculoskeletal Injuries

Higher Education

ergonomics practices in manual selection operations

Musculoskeletal injury rates in grocery and related products continue to be approximately twice the overall industry average. Most of these injuries in grocery distribution centers (DCs) are experienced by the “selectors” who are the people lifting and moving full cases of products from warehouse storage locations to pallets or conveyors for shipment to individual grocery retail stores. In additional to full case selection, many of the facilities also have a piece-pick operation in which individual items are manually selected for shipment to retail sites.

While there is movement within this industry toward the creation of automated facilities, the cost to create an automated facility suggests that manual product selection operations will be continuing for quite some time. Thus, research was conducted at The Ohio State University to investigate where feasible and effective ergonomics practices have been implemented in grocery distribution facilities that can be shared across the industry to enhance the safety of grocery DC workers.

Ninety-seven management personnel from 29 grocery distribution centers participated in these interviews. The participants were asked a series of questions about potential ergonomics practices that had been described in Marras et al.’s (2005) white paper on grocery DC ergonomics practices and the personal experience of the investigators. While the initial interviews were conducted in person and included facility tours, the onset of the pandemic moved these interviews into the virtual world.

The identified ergonomics practices that had been implemented in the participating facilities were categorized as:

  1. Warehouse setup/organization practices
  2. Warehouse management system practices
  3. Selector tools
  4. Case pick area work practices
  5. Organizational practices
  6. Piece-pick practices

The warehouse setup/organizational practices included modifications to racking to reduce the bending required and/or provide two-sided access to the palletized products, using flow rack for slow moving products, implementing a maximum case weight for second-level pick locations, and expanded access to sale items and fast-moving products.

The warehouse management system practices focused on pallet rounding when a store orders nearly a full pallet quantity. This removes the need to manually transfer large numbers of cases. The other warehouse management system practice was employing a case weight limitation at a selected point during the palletizing process; for example, once the palletized volume has exceeded 40 cube. Cases palletized beyond this point must be less than or equal to a criteria weight (e.g. 15 lbs.). Some participants have referred to this as the “ergo” pallet.

Case hooks (aka pick hooks or pick sticks) were the most frequently described selector tool. These facilitate getting products from the back half of a pallet, especially when selecting from second-level pick slots. The challenge is creating tools that can be easily transported on the pallet jack or stored on the rack itself. Several different effective approaches were shared by the study participants.

The case pick area work practices included picking by layer, having forklift drivers rotate partially picked pallets (especially second-level pallets) for improved access, having replenishment adopt the “slide to the side” practice to maximize the space between pallets within the racks, thereby facilitating two-sided access, which in turn reduces reach distances and supports layer picking practices. Another practice in perishable warehouses is to have the banana pallets pre-layered so that selectors can essentially drive up and pick up the required quantity of banana cases with minimal to no manual lifting. There are different types of layer picking equipment available that can facilitate this process for the workers preparing the banana pallets.

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