Manufacturing Quality Management - A Guide
What is Manufacturing Quality Management?
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.
Defects and their Consequences
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.
The Role of Business Processes
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.
What makes Manufacturing Quality Management Challenging?
Quality management in manufacturing is made challenging by many factors including Product Complexity,Manufacturing & Supply Chain Complexity, and Customer & Regulatory Complexity
- Product Complexity
- Increasing product configurability that results in many product variants
- Rapid rate of change resulting in many versions of a product and associated components
- Increasingly challenging product specifications
- Complex Bill of Material (BoM) structures
- Manufacturing & Supply-Chain Complexity
- High-product-mix requiring smaller production batches that require frequent equipment change-over
- Multiple factories; many cells and work-stations within factories
- Globally distributed supply chain
- Multi-tiered supply chain with many critical sub-tier suppliers
- Customer & Regulatory Requirements
- Medical Devices: Increasing FDA oversight on supplier quality
- Semiconductor: Increasing sensitivity to component variability driving stringent Copy Exact requirements
- Automotive: Increasingly stringent recall rules
What is Quality Control?
What makes Quality Control Challenging
Root Cause Analysis
The Role of Quality Management Systems
In the previous section, we learned about the importance of business processes, and how every business process — from order to delivery — must be well defined, and flawlessly executed to deliver a great customer experience.
The ISO standards - ISO9001, AS9100, ISO13485, IATF16949 - recognize and reinforce the importance of robust business processes, and therefore, these standards require companies to: (1) document their business processes, (2) ensure their employees are trained to operate the business processes, and (3) maintain records demonstrating that the business processes are operating as designed.
Most manufacturers have hundreds of business processes to operate, and therefore require a Quality Management System (QMS) to ensure processes are documented, employees are trained, and processes are operating as designed.
Typical business processes include:
- Purchasing Raw Materials or Components
- Product Assembly and Test
- Managing Non-Conformances
- Managing Gage Calibrations
- Managing Changes to Engineering Drawings and Specifications
- Equipment Maintenance
What is a Quality Management System (QMS)?
So what exactly is a Quality Management System (QMS)? Contrary to popular belief, a QMS is usually NOT a single system. Instead, a Quality Management System (QMS) is a combination of software systems with which a company ensures processes are documented, employees are trained, and processes are operating as designed.
The image above shows a typical combination of software systems that make up a Quality Management System. Modern software blurs the lines between many of these systems. For example, some PLM systems may have built-in Document Control capability. As a result, every company's Quality Management System will be at least slightly different.
For example, the business process for purchasing raw materials may be documented in the Document Control system, the employee training logs maintained in the Document Control system, but the purchasing process itself may be operated entirely in the ERP system (A typical purchasing process involves a Purchase Requisition created and approved within the ERP system, then delivered to a Buyer, who then converts the Purchase Requisition into a Purchase Order (PO). The buyer negotiates pricing and delivery terms and then issues the PO to a supplier. The supplier then ships the required material, which is received into inventory via the ERP system.)
Regulators, certification bodies, and your customers will periodically audit your Quality Management System. They are all looking for assurance that your business processes are documented, your employees are trained, and your business processes are operating as designed.