Human Errors: Lessons from Warehousing

For years I have been informally researching how humans make decisions including the biases and rules of thumb that often lead to suboptimal decisions. Every day I fall prey to at least a couple of them; some of them more than once daily - just to be sure I do it properly. In the right context, this strategy of decision-making can be adaptive, helping us to make quick and better decisions that are better than the deliberative alternative. In the wrong context, they can lead us astray.

In the warehouse setting where I work, the environment involves many different tasks that need to be followed exactly to get the right product to the right customer in the fastest possible time. Human errors can creep in at any stage. The wrong products are picked from the shelves, the ‘checker’ does not notice the picked product is not correctly listed on the customer invoice or the right parcel is sent to the wrong customer. These are just some of the errors that can creep into a process that should seem straightforward in theory but becomes complex in practice. We could explain human fallibility based on the fact that humans are complex adaptive systems. ‘Complex’, in the sense that we consist of many interconnected parts with billions of brain cells involved in ‘computing’ is the best option between alternatives in the blink of an eye in an everchanging environment. And ‘adaptive’, because we are co-evolving within the environments inside which we function. As environments change, we adapt to them, causing the environment to change, leading to more adaptation and so on.

Whether you are a blue-collar worker or part of top management, we function inside other complex adaptive systems (CASs) we call ‘organisations’. Taken together, humans as CASs and businesses as CASs creates the perfect environment for errors, showcasing our human fallibility. Human error can never be completely extinguished. But being aware of the mental workings that give rise to some of those errors can, at least, reduce their likelihood and impact.

The mental errors I describe here are not only prevalent in a warehouse/logistics setting but can be seen in other contexts such as writing proposals, verifying data on a spreadsheet or following a routine process and doing the same task repeatedly.

• Confirmation bias – seeing cues that resemble exactly what you are looking for and thus not noticing slight differences or changes in a report or a checkbox and ignoring other disconfirming information
• Related to confirmation bias is inattentional blindness and change blindness. The former occurs when you look at an object (e.g. data or a detailed report) but do not notice something right in front of you because you are looking for something more important at the time.
• Change blindness occurs when something (e.g. strings of data, a sentence or a paragraph) has changed in a document and you fail to notice the change when re-reading the document
• Priming occurs when exposure to a particular stimulus (e.g. clothing sizes: S, M, L, XL) influences your response to a subsequent stimulus (e.g. when you keep picking the same size as previously even though it might be the wrong size)
• The transience of memory: the natural fading, short-lived nature of memory means that we forget small pieces of information or misremember information over time
• Divided attention: when trying to pay attention to more than one stimulus at once, our attention jumps between tasks, increasing cognitive load, thereby further increasing the likelihood of errors while also increasing the time per task

Awareness of these cognitive errors may not completely erase their existence, but at least reduce their likelihood and impact. Awareness, after all, is the first step towards striving for excellence.