If you work in a Lean manufacturing environment then I am sure you strive to remove waste. I recently read a conversation thread on LinkedIn on the topic of Quality. A question was asked if quality inspections added any value. You can see the post here.
I thought the original question is a great example of how the concept of a Lean manufacturing solution must be examined within the greater scope of how a business operates in order to really identify if an activity is wasteful. Let me explain.
First, to clarify, I fully agree with the statement that quality inspection is part of Quality Control (not Quality Assurance), where the objective is to separate defective product from defective-free product. I see Quality Assurance as the practice of preventing defects by establishing the proper designs, processes and trainings before a product is built. In other words, if you can design and build a product that is defect-free, then you have eliminated the need for quality inspections, thereby removing waste from your process. This is what I call “nirvana” for a Lean guru. I see this as a direction to work towards, but one that will never be actually achieved. This is a critical assumption. My rationale is that there are too many variables that are part of the production process. It is unreasonable to believe that at any one time a random event will NEVER occur. Rather, by its very nature, random act occur unpredictably, which means they can’t be “planned” away.
Given this assumption, if you choose to not perform a quality inspection during your production process, then some products will be shipped with defects. If this is acceptable, then don’t perform a quality inspection. Perhaps you are the low cost producer for your market. In that case, your customers might be forgiving and simply throw away an occasional product as long as most were acceptable. I would propose, however, that if this scenario describes how you operate, then you are exposed. A competitor could potentially steal your market share and customers, which leads me to the first way that Quality Inspections add value.
- Final quality inspections are the last activity you perform before product is shipped, so represent the only true perspective of your customer’s buying “experience.” If you lose perspective of what this experience is like, then over time you will lose perspective of how your product is perceived in the market place – leaving a wide open hole for your competitors to offer new value to your existing customers.
Another benefit of implementing both a Quality Assurance and a Quality Control program is that the inspection process can provide valuable manufacturing intelligence that can then be used to design better quality products and processes. Every continuous improvement program is reliant upon gathering data to improve efficiency. Where will this data come from? This brings me to point #2:
- Quality Inspections are a source of data and manufacturing intelligence on how your production processes are performing; they provide insights into how a better design might lead to higher quality and less waste. Statistical Process Control (SPC) analyses can be performed on your Quality Control data (i.e. inspection results) to gain insights for process improvement along your entire production process.
At the start of this post I suggested that those who don’t understand the value of quality inspections were not looking at the “big picture.” The cost to deliver a product extends beyond the build cost – it continues to occur across the entire lifecycle of a product, from delivery, support and warranty claims, all the way through disposal (for some products), which brings me to point #3:
- Quality Inspections can help to reduce future costs, including rejected or returned items (perhaps damaged during shipment based on a packaging defect), higher warranty returns or more calls into your customer support center to answer questions such as “What happened to all the bolts I need to build my outdoor table set?”
All in all, quality inspections can be a source of considerable value-added activity, but perhaps more as a cost reduction and competitive defense tool, rather than as a justification to raise prices. But, in the end, if more money is flowing to your bottom line, isn’t that a value-added activity?