Are You a Sheet or Shelf Thinker?

My first job was in industrial distribution, and with distribution came learning to count inventory. An annual inventory tax was levied, so an accurate count was important. I was given a computer list of items to count. An important lesson I learned was that to get an accurate count, there was a right and wrong method.

Given the computer-printed inventory sheet with item description, bin location, and the inventory count shown in the system, I found myself verifying the sheet rather than counting what was actually on the shelf. This led to a huge disparity in the inventory count.

The reason for the wrong count was that as I read the sheet, I would look for the item on the shelf. If the sheet matched what was on the shelf (e.g., description, quantity), the count was reported as accurate or else adjusted to the appropriate number.

However, items had been misplaced when shipments were received or accidentally moved for a variety of reasons. Items reported missing during the inventory count when counting sheet-to-shelf were actually there in many cases, just not where they were supposed to be.

So the problem for my inventory was counting sheet-to-shelf rather than shelf-to-sheet. With the latter method, I might have run across a misplaced item and still been able to count it. I missed items when I was only looking for those on the sheet.

The problem was simply one of method. Shelf-to-sheet was the better way to count inventory so no items would be missed.

Sheet-to-shelf: the wrong method

This “sheet thinking” has been perpetuated in the methods used to improve organizations. For instance, we have the seven wastes of manufacturing that are applied to service industry. Beyond the fact that manufacturing and service are different, and copying is always a bad idea, the method is also faulty because by looking at improvement in a sheet-to-shelf fashion—i.e., reading from someone else’s list—we may miss other forms of waste. Sheet-to-shelf thinking is a “seven wastes” approach that we try to apply regardless of the industry.

This is a problem with tools- and method-based approaches that begin by copying what others have done. Companies that do this miss the opportunity to discover other forms of waste or uncover better thinking. This limits the possibility of breakthrough performance.

Shelf-to-sheet: a better way

No two systems are the same. When we try to improve using sheet-to-shelf thinking, we wind up copying what another organization has found and miss the real causes of waste in our systems. Conversely, if we identify problems such as waste, design, and thinking that are unique to an organizational system, we are employing a shelf-to-sheet mentality.

Using the Vanguard Method, the three questions I have learned to ask before any tool is ever used are:
1. Who invented the tool?
2. What problem were they trying to solve?
3. Do I have that problem?

Most of the time this doesn’t come up because the approach I use doesn’t require tools. However, for those endeared to the sheet-to-shelf tools approach, a warning label should accompany the tool with the above three questions attached.

In order to improve performance in any system, we must study the what and why of current performance without assumptions or using tools that limit thinking. Doing otherwise is copying what someone else discovered in their system, not yours.

The shelf-to-sheet method requires some follow-up to achieve breakthrough improvement. It’s important to understand that the system drives performance, and that management thinking governs how a system is designed.

When thinking is in play, we can challenge assumptions that dictate the current design of work. Assumptions about managing costs, functional design, decision making, targets, motivation, and technology get a healthy analysis, and can be challenged more readily when taking a shelf approach. The design and management of work is the issue, not the use of improvement tools.

In an interview with W. Edwards Deming during the 1980 NBC television show, If Japan Can, Why Can’t We? Deming warned us against copying the Japanese, “American management thinks that they can just copy from Japan, but they don’t know what to copy!” Yet, too many improvement efforts are based in just this type of thinking. He challenged us to better thinking, not learning Japanese words to improve. In fact, I have found that native tongues and engagements without tools work better in improvement efforts.

All organizations and individuals have a choice in how they approach improvement. One approach is copying (or using tools); the other is thinking.

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