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
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