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How Human Factors Affect Warehouse Productivity

Posted by Amanda Honig

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April 21, 2016 at 7:00 AM


It’s all in the wrist. It’s a phrase you often hear said about professional tennis players or really good major league hitters. Hank Aaron and the late Ernie Banks come to mind. Its meaning is basically that you can achieve the result you want—acing a serve or hitting a home run—using less strength and more control.

It’s also a phrase that has much to do with maximizing worker productivity in today’s retail warehouses or distribution centers. Addressing worker productivity challenges requires a thorough understanding of the science of human factors in warehouse operations. At Zebra, our Innovation and Design team carefully examined the everyday challenges in today’s warehouse practices. The research, detailed in the white paper Addressing Productivity Barriers in the Warehouse, revealed valuable insights that led to the development of our new TC8000.  

Human factors research

In today’s omnichannel warehouses, forearm and wrist movement have major implications regarding industrial design and making more efficient processes possible—including picking, packing, put-away and cycle counting. In addition, they can also cause physical worker issues like stress, injury and fatigue. That’s why traditional dual plane handheld computers that force workers to “tilt and verify” are major contributors to loss of productivity, and why our human factors research testing process specifically addressed the physics of hand posture and hand strength as they apply to warehouse activities.

Side-by-side testing

The studies involved four phases:

  • Observational research to demonstrate actual warehouse worker needs.
  • Usability testing to improve ease of use.
  • Ergonomic evaluation to minimize the physical stresses associated with task execution.
  • User-centric industrial design that posited the added value of a single plane, “line of sight” touch-screen design.

Gun-style dual plane computers were tested against a prototype single plane design unit. Ten experienced warehouse workers were asked to perform four typical tasks with each:

  • Scan a shelf location.
  • Verify the location code shown on the device screen.
  • Scan a product at that location.
  • Verify the product number appearing on the screen.

Measurements included time to task completion and muscle effort and wrist motion.

Reduced movement

The data collected was enlightening showing considerable reductions in movement and muscle effort for single plane units versus gun-style warehouse devices:

  • Wrist movement (total degrees of movement) of single plane units at high, mid level and low shelf heights showed a 55% reduction in wrist motion for tilt and verify tasks.
  • Muscle effort showed a reduction of 12.3% (mid to high shelf) to 22% (low shelf) for single plane units for scan and verify.

Movements of the hand and wrist were measured in two anatomical planes: flexion/extension and ulnar/radial deviations. These studies found that hand strength is at its maximum when the hand is aligned in a straight line with the arm, as in the new single plane computer design. Any deviation, as in traditional gun style designs, results in:

  • A reduction of hand strength
  • More user fatigue
  • Increased opportunity for error

These results were confirmed in controlled tests in an actual working warehouse.

Maximizing hand strength

Based on these test results, Zebra engineers created a new category of warehouse mobile devices. The new single plane TC8000 design allows users to keep the hand, wrist and forearm in alignment, resulting in maximized hand strength. Tests revealed significant opportunities to increase productivity by eliminating the non value-added wrist movements dictated by the old gun-style handheld computer design. Furthermore, these gains could be accomplished with less physical effort from workers.

The bottom line?  The more ergonomically designed TC8000 mobile computer empowers warehouse workers to boost productivity by accomplishing more tasks faster, and with less effort and less risk of injury and fatigue.

To find out how the TC8000 can help you increase warehouse productivity, read the white paper Addressing Productivity Barriers in the Warehouse. 

Amanda Honig is the Americas Product Marketing Manager for Handheld Enterprise Mobile Computers at Zebra Technologies. Amanda works closely with Zebra’s product development and global marketing teams to introduce new mobile computing solutions to customers across all industries.

Topics: North America, Warehouse Management, TC8000, Warehouse, Productivity