I first started working in the aerospace industry in the early 1980s. After 40 years in the industry, I have been able to accumulate a very different perspective of what is really needed to improve aerospace quality.
I also owned a manufacturing company in the high-tech industry providing products for IBM, Hewlett Packard, Digital Equipment and Sun Microsystems. The company I owned was a company in Scotland called Fife Fabrications. Fife Fabrications was pretty run down when I bought it, but after a series of major changes in the first few months it became a showcase for on time delivery and quality (see reference to Fife Fabrications in my book “The Art of the Turnaround” now available to preorder on Amazon).
What drove our high level of performance was our customers’ requirements that we met a true measurable six sigma quality process of 3.4 defect parts per million in our manufacturing process. The customers also demanded on time delivery with no excuses. Winters in Scotland were brutal, so on many occasions we left very early in the morning to make sure the deliveries were on time at our customers’ destinations. This was the norm in the industry, and like the life insurance salesman’s motto, “if at first you don’t succeed, that’s it”. Your contract would be cancelled if you did not meet requirements of delivery and quality. One advantage the customer had was that there were many companies capable of making your parts, so unlike the aerospace industry they had a way of strongly encouraging you to perform.
Prior to this I had become a partner in an aerospace company in Everett Washington. The company made swaged tubes for all the major aerospace OEMs with a significant amount of the production going to Boeing. This supplier was also having financial problems, and I was initially brought in to get the company back on its feet. This company turnaround was my first introduction to the eclectic aerospace industry.
When I started the turnaround process, I was genuinely shocked at the overall manufacturing quality and the philosophy of go or no go. The inspection of the part we manufactured was very binary. It was either good or bad. There was no concept process control, just good or bad. There was even another category of quality that was allowed and that was the ubiquitous advanced rejection tag. This was a process that allowed you to ship a product to the customer that was out of tolerance on what was called an advanced rejection tag. The customer would then review it and determine through their engineering whether it could still be used or not. Understanding the importance of manufacturing aerospace parts, the quality standards seemed very loose and encouraged suppliers to avoid process improvement to eliminate variation in the manufacturing process. One of the challenges in aerospace is that quite a significant number of the parts are machined from forgings and castings which are not only very expensive but have extraordinary long lead times. The lead time for forgings and castings can be over a year so a concession for a minor quality issue is understandable. Unfortunately, this attitude of making do creeps into all aspects of quality and explains some of the issues that have recently gained publicity.
The aerospace industry is one of the most complicated industries in the world with logistic and supply chain complexities that makes it mind numbing to even understand.
On a commercial jetliner there are close to 300,000 part numbers. Each part has multiple features that have to be manufactured to a precise specification, sometimes with tolerances as small as a plus or minus a ten thousandth of an inch. This is a tolerance of 5 microns or a third of the width of a human hair. On each part you can have on average 50 features. This means, at an aircraft level, you have close to 15 million points of failure. Add to the aircraft two engines, and you can add another 60,000 parts with on average 50 specified features per part you have another 3 million points of possible failure. In total 18 million potential points of failure that must be met every time an aircraft is built.
Maybe this will help educate the armchair quarterbacks who grossly underestimate the complexity of what it takes to build a single aircraft.
To further add to the complexity the average OEM (Original Equipment Manufacturer) has over 2,000 first-tier suppliers and close to 5,000 sub-tier suppliers. The sub-tier suppliers can be four layers deep so supplier D at the bottom of the food chain makes details that go to supplier C for assembly. Supplier C then sends it to Supplier B for additional assembly. Supplier B the sends the completed assembly to Supplier A who is the supplier to the OEM.
At every stage quality must be managed. Because of the complexity of making the first part and meeting all the specifications, normally each company is the sole source for their particular part numbers, and it is a significant undertaking to move parts from one supplier to another, as you have to repeat the whole certification over again. Unlike the automotive industry where the OEMs have multiple choices the aerospace industry does not.
As OEMs require their suppliers to constantly reduce their prices a new phenomenon occurred. Each level of the supply chain looked for a lower cost supplier further down the food chain. This added additional supply chain levels and financial friction to an already stretched supply chain. All this was done to try and reduce their costs. This meant that some parts now start out in Vietnam or South Korea and eventually end up at the OEM fully assembled into a complex assembly in Renton or Charleston South Carolina. Airbus has similar system with even large national subcontractors.
Now with this stretched-out supply chain you now must monitor quality and production through this global web where in many cases it is impossible for the OEM to even know who the suppliers of the suppliers are. Remember all this with 18 million places where a part can be out of tolerance.
The industry also produces vast quantities of paper. Millions of documents are scanned every day, forever losing the valuable metadata on the documents. The digital age has a long way to go in the aerospace industry. Utilization of data is going to be a major ingredient in improving the quality in the industry. Because of its complexity the industry will benefit from all the digital transformation taking place including the use of cloud computing and machine learning.
With all this complexity in 2023 8.6 billion people flew safely in commercial aircraft worldwide with only 72 on-board deaths. In the USA it’s been 15 years since there was a fatality on a commercial aircraft. Globally last year 1.25 million people died in car accidents and five times more than that seriously injured. This would be equivalent to 17 commercial jets crashing every day. There would certainly be congressional hearings.
Even with this remarkable safety record quality can be improved to eliminate defects, speed up the supply chain, and dramatically reduce maintenance costs. Another major improvement can come from the reduction of warranty reserves on the balance sheets of the major aerospace companies. This should be a major incentive for the C-suite as the reduction in warranty reserves goes directly to the bottom line.
The five detailed steps for improving quality will be part of a series of additional blog posts published on a weekly basis
- Utilization of technology in all aspects of manufacturing
- Process improvement using Taguchi method of target nominal
- Real root cause identification and effective corrective action
- Frequent equipment replacement
- Automation and determining equipment capability
