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

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 aspects today is the communication interface between the computer system and the operator. And as I have discovered, what may seem perfectly logical in an information flow diagram or a conference room pilot frequently provides disappointing results when the process moves to the floor.

At the systems planning stage, the primary focus of the discussion is on: the information communicated to the operator, how the operator is expected to respond, and the mode used to communicate the information. The choices made at this time have a significant impact on the productivity of the operation.

Let's consider how the data system/human operator interface can get in the way, and the options available to boost productivity and maintain process integrity.

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

• Operator scans the license plate label on the inbound carton with a wireless terminal.
• Terminal displays pick face location on its 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 as well as re-handling of the terminal. A re-engineered process might go like this:

• Automatically scan the carton on the inbound conveyor with a fixed scanner.
• Print the put-away location on the carton with an ink jet printer.
• Organize the incoming cartons in groups to minimize walking.
• Place the carton in the location and use a wireless terminal to scan both the carton and location label.

The second scenario acknowledges the value of seeing the put-away location, and requires handling the wireless terminal once. A savings of 10 seconds in this one-minute transaction reduces replenishment labor by 17%.

But there might still be a better way to work. While these terminals eliminate paper and permit real-time inventory and order updates, there is often a slow down in pick rates due to the handling of the terminal.

Substituting a voice system for some of the information transactions supports real-time, paperless operations and frees both hands for maximum picking productivity.

Typically, we debate the relative merits of one form of information transfer 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 information transaction on the tasks at hand? You bet it would.

Jim Apple can be contacted at japple@theprogressgroup.com