The top barrier to process productivity

Variation.  Let's break this down.

Incoming variation from providers - if you have incoming variation, you cannot eliminate it easily unless you can blend it away. Blending is not lean.  It is not always a solution when you are buying parts or services and not powders or liquids. It builds up in each step of your process like vibrations in a speaker, getting louder at each step as every other process variation adds to it. Eventually you have product and processes out of control and out of specification. 

Work with your providers

Price is certainly not everything. If you haven't learned that yet, keep reading. Lowest cost providers give you lowest cost product. Lowest cost product is produced in lowest cost environments, and unless they are lowest cost due to extremely high levels of quality control, you are getting incoming variation that will cost you in the end. Partnerships with providers give you opportunities to match up your process requirements with their product characteristics, and most often a partner supplier will give you a fair price because of the value of the partnership.

Process Variation - this covers everything from multiple production lines to work instructions to controllers to people, etc. Variation happens. Entropy is a natural law and will eventually set in. Does this mean that zero defects is not possible? Absolutely not. 

Create the mindset of zero defects

Tighten the process variation tight enough and you will not produce defects. Use your problem solving toolbox and dedicate resources to variation reduction. Your customers, your business, and your shareholders will thank you.  And they should. Start at the beginning of the process to save time, because as stated above, the end product is the result of all variation up to that point!

Organizational Variation - my favorite one, because it lets me quote my favorite organizational quote: "In order to optimize a system, you must sub-optimize its sub-systems. If you optimize the sub-systems, you sub-optimize the system." Let's look at an example. If you are building an engine and you maximize the structural strength of the intake manifold, but don't account for the lack of expansion due to the change in strength, something else is going to break. And when it does, someone will be on the side of the road wondering why they bought your product. Maintaining consistency is difficult when the cylinders are not all firing at the appropriate time. 

Continually tear down silos

All sub-systems need to work together for the benefit of the product and the organization. Tear down walls and unnecessary procedures, increase communication to ridiculous levels, utilize change management strategies, and create cross-functional teams. Design for productivity - involve production in product design and development. Bring your supply chain into your production and design conversations. Hire great people so you can accomplish great things. 

Variation in demand - start-ups, shut-downs, line clearance, these all create variation and waste. Is it outside of our control? It certainly feels like it. This is probably the most challenging aspect of process variation to conquer due to the external influences of the customer and the market.

Design for flexibility

Think outside the box on this one. Running a line slower but with fewer or no shut-downs may do the trick. Why do this instead of running all out and finishing with a low labor/overhead cost per unit? Unless you are sold out on capacity, finishing earlier on a job doesn't gain you much. Labor and overhead just moves into another bucket or another job that goes into inventory. It's difficult for production managers to accept that running slower gains you efficiency and quality because that is opposite what they are used to doing. 

There are many ways to drive out variation since there are many forms of variation inherent in our daily lives. When quality is defined as consistency through time, driving out variation gives us the highest levels of quality. Consider your morning coffee and your expectation for flavor, texture (mouth-feel), temperature, aroma, and speed at which you receive it. Variation in any of these is noticeable and affects your decision on your next cup. Keep variation in your process and products to a minimum and your customers will continue to be delighted.