“A Thief in Hiding”

You may recall the admonition to the materials handling system suppliers that the human workplace should be designed before the mechanical system serving it. Well, like mechanical systems, the interface between the computer system and the operator needs to be thoroughly analyzed before committing it to code.

When we design warehouse processes, it’s easy to focus on the walking time required for picking. Historically, it has been the largest portion of the largest task in the warehouse. But, as we get better at shortening the pick path, the other parts of the task begin to get bigger. One of the most critical is communicating between the system and the operator.

What may seem perfectly logical in an information flow diagram, and may even look fine in a conference room pilot of the system operation, frequently provides disappointing results when the process is implemented on the floor.

What information we communicate to the operator, what we expect in return, and what mode we use to do it are vital to the integrity of the operation. At the systems planning stage, this is normally the primary focus of discussion. However, the choices made at this time have a significant impact on the productivity of the operation, as well.

Let’s examine a couple of places where communications has gotten in the way, and some options available for changing the mode so that it enhances productivity, and maintains process integrity.

The typical process description for replenishing cartons to the pick face is:

• Scan the license plate label on the inbound carton.
• System displays the pick face location on the terminal screen.
• Operator walks to the pick face with the carton
• Operator scans the location label on the pick face, and perhaps the carton again.

This all seems logical, and maintains inventory integrity, but requires significant walking and re-handling of the scanner.

A re-engineered process might go like this:

• Automatically scan the carton on the inbound conveyor.
• Print the put-away location on the carton with an ink jet printer.
• Operator can organize the incoming cartons in groups to minimize walking.
• Place the carton in the location and then scan both the carton and the location label.

Both alternatives are supported by the same WMS functionality, but the second acknowledges the value of seeing the put-away location, and requires handling the scanner only once. A savings of 10 seconds in this one-minute transaction reduces replenishment labor by 17%.

RF terminal directed picking is rapidly becoming the norm, as it eliminates paper, and permits real-time updating of inventory and order status. The big surprise for many users has been a slow down in pick rates resulting from the handling of the scanner, screen and keyboard.

However, substituting voice recognition communications for some of the transactions has permitted maintaining real time, paperless operations and getting the productivity advantages of having both hands free to do the picking.

Rather than debating the relative merits of one form of communication versus another during the design phase of the system, wouldn’t it be better if we had detailed engineering studies of each alternative that could help us understand the productivity impact of each of those boxes and lines on the information flow diagram?

Let’s put the industrial engineers to work!

ABOUT THE AUTHOR

James M. Apple, Jr. is a Director in The Progress Group. Prior to co-founding The Progress Group in 1991, he was a Partner with Coopers & Lybrand's SysteCon division. During 1992-1995 he served as a Senior Systems Advisor with Vanderlande Industries, a major conveyor and systems provider in Europe.

Jim is an internationally recognized thought leader in the area of facility design and integrated distribution systems. His contributions to the improvement of distribution practices have been recognized by his receipt of the prestigious Reed-Apple Award, which is given for lifetime contributions to the advancement of the material handling profession. Jim has also received the Institute of Industrial Engineers' Facilities Planning and Design Award. He has written numerous articles and handbook chapters on warehousing and logistics operations and is a popular speaker on logistics seminar and conference programs.

Prior to SysteCon, Jim worked as an Industrial Engineer with IBM, was Supervisor of Facilities Planning for the Oldsmobile Division of General Motors and was Executive Vice President for an automotive aftermarket parts supplier. He holds B.S. and M.S. degrees in Industrial and Systems Engineering from the Georgia Institute of Technology.