Quality Control: From Raw Material to Delivered Product
Delivering Defect-Free Products
Manufacturing Quality Management is the science of defining and executing all the business processes — from order-entry to product-delivery — to ensure that products are consistently produced to specifications.
When a component or product is not to specifications, we call that a defect. And when any business process — from order to delivery — breaks down, we end up with defects. Defects result in internal and external costs of poor quality to organizations. Internal costs of quality include the cost of rework, scrap and wasted capacity. And external costs of poor quality include the costs of returns, warranty, and loss of customer goodwill.
Where do Defects Come From? A Business Process Perspective
Business Processes play an important role in an organization's ability to deliver high quality products. To understand what processes are involved from order to delivery, let's start in a coffee shop. It's one of the most transparent businesses you can observe and experience.
And just like in a coffee shop, in the modern manufacturing environment, hundreds of business processes - from order entry through product inspection and test - need to function flawlessly in order to ship a defect-free product.
The best coffee shops deliver a delightful customer experience. This customer experience is a combination of the cafe's environment, order accuracy, wait time, and the attributes of the coffee including its taste, aroma, temperature and consistency. The wait time and cafe environment – the seating, lighting, and noise-levels - can make or break the experience, but for now we'll focus on just the order to delivery process and the taste of the coffee.
We've all had days when our coffee orders were messed up. This happens more often than we like, and even happens to us at our favorite coffee shops! Your coffee order can go wrong in two ways:
- An Error or Mistake: You got the wrong drink.
- Your order was written incorrectly by the cashier
- The barista made the wrong drink
- The barista missed an important ingredient
- Variation: Your coffee tastes different.
- Your coffee was over-brewed and tastes burnt
- Milk temperature was not set correctly
- Water pressure was too low or too high
Let's track your coffee order from order-entry to delivery to see where things could go wrong. As you can see, your order can be messed up at any step from order-to-delivery.
Coffee: Order-to-Delivery Process
So how does a coffee shop get to zero defects? Focusing on the make process (i.e. focusing on the work of the barista) will eliminate some of the defects. But as you can see, defects can also be caused by the order-entry process or introduced by weaknesses in other supporting business processes. For example, coffee machines must be maintained and cleaned. A steam wand that's not cleaned results in poor quality foam. Similarly, inadequate inventory management process could result in milk being used past its expiry date.
This is an important point. Very often companies assume that all their defects originate in the "make” or manufacturing process, and they focus all their efforts on the worker (in this case - the barista). This flawed assumption prevents companies from ever getting to zero defects. Defects can originate at any point from order-to-delivery, and therefore the path to zero-defects requires robust business processes at every step along the way.
Sources of Defects in Manufacturing
As an example, let's follow a piece of semiconductor capital equipment (machinery for chip manufacturing) from design through installation at customer site. In this business, teams must design the machines, configure the machines for each customer's requirements, buy the parts to make the machines, assemble and test the machines, then ship them out to customers around the world. When the machines reach the customers' factories, they need to be installed, and activated for the customer to begin production.
As you can see from the process flow diagram below, there are many business processes from order through delivery and installation. And as a result there are many possible sources of quality problems. Here is a partial list of where the defects come from, and the types of defects, based on my experience in this industry.
Order-to-Delivery Processes for Machinery Manufacturing
As you can see, a defect can be introduced at any step along the way, from the design and engineering processes, to the installation and startup process.
And if an equipment manufacturing company focused on only the "manufacturing" (assembly and test) process, they would never get to zero defects. Instead, the path to zero defects requires an organization-wide attention to detail, and a mindset of continuous improvement towards ALL the business processes from product design to product-usage.