December 2012 | Commentary | The Lean Supply Chain

Playing the Waiting Game

Tags: Lean

Paul A. Myerson is Professor of Practice in Supply Chain Management at Lehigh University, and author of Lean Supply Chain & Logistics Management. 732-441-3879

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We all want to do our jobs, and are paid to do so. Often, however, we must wait for information or materials from suppliers, supervisors, other departments, and even customers. While we wait, we can get distracted and end up wasting even more time.

In Lean terms, waiting is one of the eight wastes. Identifying the root causes of delay allows us to improve the flow of materials, people, and information through the supply chain.

Working as a team using some basic Lean tools is a good way to begin reducing this type of waste. In a warehouse environment, for example, the start of a shift or wave can be unproductive as workers stand around waiting for assignments. Observing the current process for non-value-added activities enables us to make significant improvements.

Ask the following questions to streamline your warehouse shift or wave start-up:

  1. Do you have a standardized, visual start-up process? Creating visual job aids with digital pictures and easy-to-understand steps in English, Spanish, or any language relevant to your workforce speeds activities such as putaway, picking, packing, staging, and loading—and results in less variation in worker performance.
  2. Is the layout conducive to flow? If workers have to wait or search for instructions and tools instead of going to a set area to get the information themselves, they will waste time. For a receiving area, ensure documents and instructions are easy to find and ready to go. It's also a great idea to set up supply carts with all the tools and forms workers need to unload and receive shipments or load trucks.
  3. Is there a place for everything? Use clearly visible and understandable signs to organize tools, materials, and information. Workers won't have to wait or search for items such as cleaning tools, handtrucks, forklifts, and supply carts.

Simplify Supply Lines

When workers in a warehouse shipping or receiving area run out of supplies and materials, they must wait for the needed items to be re-supplied. A kanban system—material replenishment based on the pull of downstream demand—is a useful, visual tool to ensure a steady supply of materials. Create a simple kanban by putting a line on a wall indicating the level at which materials need to be replenished. To be successful, you need to occasionally adjust the line based on the current average demand.

If a kitting or assembly line is unbalanced, people on the line will spend time waiting. A good way to identify imbalances is to use a Time Observation Form to document each step in the process, evaluating each activity's actual processing time compared to its estimated Takt time (demand rate).

Additionally, if forklifts, trucks, and conveyors aren't properly maintained, the operators must wait, and other supported processes suffer from delays. A Lean tool called Total Productive Maintenance focuses on minimizing equipment-related waste by improving equipment uptime and productivity.

If we resign ourselves to waiting, and assume it is part of the job, nothing will change. Focus on non-value-added waste to make your workplace more productive.

Parts of this column are adapted from Lean Supply Chain & Logistics Management (McGraw-Hill; 2012) by Paul A. Myerson with permission from McGraw-Hill.