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Quality Control (Quality Assurance)

Most boat builders and manufacturers believe they are making a quality product. What does that mean?

Quality control is simply the process by which you make sure every product you turn out is the same as the last in terms of construction, reliability, durability and appearance.  Quality control does not mean you have a quality product.  To have a quality product you must start with design, the components that go into the product, and the workmanship when building it. Quality control is repeatability. Quality assurance is basically the same thing but also implies that it is also a quality product.

So what is quality?  Quality is relative. Quality is relative to price, workmanship, and intended use.  If you are building a work boat for hauling fifty five gallon barrels of oil around, you are not going to give it a yacht finish. But you  will build it to take a beating and be very reliable.  In short, a quality product for the intended  use. But if you are building a high priced boat, that is touted to be a quality product, then you do not want problems with minor things like lights that don't work or a finish that has cosmetic defects. A quality product does what you intend it to do, reliably and for a long time.

Even if you are building something with a yacht finish the quality of the product depends on the intended market. Is your product intended for entry level, low cost market, or high end, spare no expense, high cost market, or somewhere in between? The amount of time spent making it, and the cost of the parts and materials determine the cost of the finished goods, which determines the price the customer pays. This doesn't necessarily mean a low cost item is a piece of junk. If it is put together well, with good materials it can be a high quality product and still have a reasonable price.

How to Make a Quality Product:

So enough of philosophy.  Now for the more practical side of quality control. Control is the key word here.  You need to control your processes as well as the parts and materials you use. 

For instance, fiberglass laminate lay-up; the quality of a fiberglass laminate is dependent on the type of glass, the resin, the resin glass ratio, and the lay-up schedule and the ability of the person doing this. In each hull you want the laminate to be as nearly the same as possible from boat to boat. This means putting in place procedures that make sure that the same amount of glass, the same amount of resin, the same cure times, are all used to get a consistent product. The same goes for wood products. If building a plywood boat, don't just buy the cheapest plywood you can.  Develop a relationship with a supplier who will get you consistently good quality wood. In a small shop this is relatively easy to do because you have direct control over what is being done.  In a larger shop with many employees it is harder because you personally have less control.

So, as the first step in the process you need to determine what the things are that need to be controlled and what should the tolerances be. For instance, laminate thickness. What should it be, and how much, plus or minus, is ok? What should be the resin glass ratio, and what are the tolerances?  Does the wood you use have to be mahogany, or will luan or one of the many substitutes do? Do you insist on real teak?  Does the lumber yard understand your needs and let you return wood that isn't up to your standards? These are just a few examples.

Each of these procedures need to be followed for every boat.  These need to be written down.  Then a process specified for achieving this.  for instance, how do you measure how much foam goes in to a compartment? Generally it is sprayed in with a gun and a certain amount is sprayed based on time. You need to establish this so it is done the same way on every boat.

How to control Quality:

You also need a means of checking.  You do not necessarily have to check every single item that goes out the door, although some do this.  But you do need to check at regular intervals. For instance one simple way of checking to see if construction of the hull is consistent from boat to boat, is simply weighing it. If you weigh each hull and they are within 1% of each other, then you are being very consistent. Another is to check the barcol hardness of the laminate. Resin glass ratios can be checked with a burn test, and so on.

Another important issue is, who does the checking. In some shops the person doing the work does the checks. In others they have a department whose job is to do all the quality checks. 

How ever you do this, you need to check important items at each step in the process, and then have an overall check for systems, finish, and other items as the boat goes out the door. This can be as simple as running the engine, turning on the lights, tooting the horn, etc.  Or it can be very detailed.  On a visit to Hatteras Yachts I noticed a worker literally repairing scratches and dings in the woodwork.  Some were so small I couldn't see them from more that a few feet away. Yet, in addition to the hundreds of other quality checks Hatteras does, an inspector goes over every surface of the boat looking for cosmetic defects and someone repairs every single one before the boat leaves the factory. That is quality control!

You don't have to be that meticulous, some would say, over the top.  But considering what someone pays for a luxury yacht, the customer expects that kind of quality control.  But you should check all the systems to make sure they are operating properly. The electrical system, fuel system, engines, lights, electronics, plumbing, etc, all should be run to see if there are any problems.  Some builders leave this up to their dealers. I wouldn't, but that is my personal preference. If you have a good working relationship with your dealers then maybe this will work for you.

Again, it is all about having established procedures that are followed consistently, quality checks that are done consistently and final checks to make sure everything is working.

Documenting Quality:

Last but not least, do the paperwork.  A history should be kept on each boat. Start a record with the Hull ID number when you lay up the hull. Have a place for every quality check and every test. Do not put just a check or date, but put down the results.  If the fuel system was checked put down, Fuel system checked, the date,  what psi, for how long. Passed, failed? Keep this record with each boat until it goes out the door, then file it with the records on the boat. For that matter you should have a separate file for each boat built.

Parts and Materials

Another facet of quality control is controlling your suppliers.  Find out their reputation before you buy. You should get to know them and have an agreement with them about delivering parts or materials that aren't up to standard.  Develop a good working relationship with them.  If you have a buyer make sure your buyer understands the need for good materials of consistent quality. Price does not always mean quality, but on the other hand cheap is not always a bargain.

If the parts and materials you are getting vary in quality, talk to your suppliers. If nothing changes, terminate the relationship and find a better supplier that will give you consistent quality.  Put something in your agreement or contract with suppliers about quality, and what will happen if they don't live up to the agreement.  Also give them incentives for providing good quality parts and materials, especially if they are always on time with the right stuff. This could be as simple as a clause saying, that after a certain period, and having met all the quality requirements, you will buy exclusively from them. Or it could include bonuses. But make sure they understand and agree to (in writing) your quality requirements.

Some Examples of poor production planning, poor production management and poor quality control:

Example 1:

A well known and highly respected manufacturer of offshore sport fishing boats produced a 26 foot center console boat which was very popular. From customer feedback they determined that the one thing they could do to make this boat better was to make it 2 feet longer. So they did.  This model was snatched up by fisherman. 

Soon, problems began to crop up.  Stress cracks began appearing in the hulls at the transom and several feet forward of the transom. Hulls began separating from the inner liner.  The bolts holding the center console in place came out.  Some owners reported that the hulls flexed so much in a seaway that they couldn't use the boat.

The concept was sound and is a frequent practice in the boating industry. So where did they make their mistake?

First; they didn't do any extensive engineering analysis of the stresses that would occur by putting the outboard engines two feet farther aft. Two hundred horsepower engines are heavy and in addition to the weight, have a two foot longer lever arm. They did not increase the strength of the structure or add any additional supporting members. They did not increase the thickness of the hull or change the laminate lay up schedule. A Finite Element Analysis and a structural analysis should have been done on the planned model. With computer software almost any engineering firm can do this.

Second; they did not do any in use testing of the final product.

Third; when customers complained the remedies given were purely cosmetic. They did not fix the problem and in many of the boats it reoccurred.

Eventually they were forced by the Coast Guard to recall all of that model line, over 200 boats. Many of the boats had to be replaced with a new boat. It was a financial disaster and ruinous to their reputation.

It was a complete failure of production planning and quality control to prevent the problems with this boat.

Whenever a significant change in the design of a boat is made the design should be completely re-evaluated and a structural and hydrostatics analysis done.  Hire a naval architect or engineer to do an analysis and make recommendations. Significant changes can result in a decrease in stability, structural strength and less load capacity. If this is a larger boat you may even need to do a stability test. See the Ethan Allen case. http://en.wikipedia.org/wiki/Ethan_Allen_Boating_Accident

Example 2.

A well known manufacturer of aluminum utility boats and jon boats had a factory in a northern mid-western state where the winters are extremely cold.  They used two part spray foam as flotation material in the boats.  The chemicals were stored in drums in an unheated area. As needed the drums were brought into the factory and used up. A boat, tested by the US Coast Guard for level flotation, failed the test. In fact it sank, indicating it had no flotation at all. Upon examination it turned out that in the compartments where there should have been foam was a pile of what looked like a cow pie, or bread dough.  It was foam that simply hadn't foamed. 

The manufacturer determined that about 1200 boats had this problem. They had to recall all of the boats to the factory, remove the bad foam and put in new. Obviously this was costly because not only did they have to redo the work, they also had to pay for transportation of the boats to and from the factory.

Here was a clear failure of production planning and quality control.

They did not take into account the temperature of the chemicals when they were used. The manufacturer of the foam specifies a narrow range of temperatures and the foam had been stored in an area where it was sub freezing and then used while it was still cold. When combined, a chemical reaction simply did not take place. The production plan should have specified that it be brought in early enough to warm up and the temperature checked before use, or stored in a heated area.

If a small sample had been blown into a test box or container before using it in the boat then the person doing this would have realized something was wrong. A test sample should always be made at the beginning of each days production, and especially on a new batch of materials.

On these boats, once the foam was blown in, the compartment was immediately covered and there was no way to check to see if the foam actually foamed up. The production plan should have specified a way to check this. For instance, simply waiting a few minutes before covering the compartment would have given at least a visual check. Occasionally a boat should have been taken off the production line and put in a test tank and given a level flotation test.

On Line References for Quality Control

Quality Engineering Vs Quality Assurance https://theqalead.com/general/quality-engineering-vs-quality-assurance/
Wikipedia on Quality Control http://en.wikipedia.org/wiki/Quality_control Wikipedia on Quality Assurance http://en.wikipedia.org/wiki/Quality_assurance
Biz/ED http://www.bized.co.uk/educators/16-19/business/production/index.htm
American Soc. For Quality http://www.asq.org/learn-about-quality/basic-concepts.html

 
American Boat And Yacht Council  Boat Design Net  Wooden Boat Foundation
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