In The Trenches
sons for this: First, if these points are
to be fixed in some manner, it is better to do this at the start of the project
while it’s still on paper.
Second, honesty with the client
cannot be overestimated. If the
client thinks — or finds out later —
that you are keeping secrets from
him, he will not be happy. (How
would you react if your doctor neglected to tell you that the medication
you were taking for high blood pressure might cause all of your hair to
fall out?)
There are always changes to the
design at this point. The client forgot
something, your approach gives him
a new idea, or some initial information was incorrect. There’s always
something.
However, if you did the first two
steps properly, these changes will
usually be relatively minor and easy
to accommodate.
Sometimes there are significant
modifications requested. This is
called a “Scope Change” and basically means that the scope, or overall
approach, of the design must be reevaluated.
In this case, it’s back to Step 1.
This Design Review becomes another Preliminary Design Review.
Another paper design must be created and another Design Review is
required.
It is important to note to the
client any significant production,
servicing, or testing considerations
here.
For example, going from through-hole to surface mount technology
(SMT) may require a substantial
financial investment in hardware and
training. As noted above, never surprise the customer.
For RFQs, this Design Review is
completed by the client. The client
examines the paperwork submitted
by the engineer to determine if it is
suitable. If so, then a contract is
awarded (or, for a contest, a prize
is given). It is at this point that the
engineer is able to contact the RFQ
client for any additional details or
questions.
Build a Prototype
This prototype (or two or three)
is a fully functional product; however,
it may not have exactly the same
characteristics as the final version.
For example, the final version may
specify tiny SMT parts that require
special machines to solder to the
printed circuit board (PCB). This prototype may use through-hole or larger SMT parts that can be handled
manually.
It used to be that prototype circuits were wire-wrapped, but this is
rare nowadays. Nearly all modern
prototypes use a PCB in order to validate performance characteristics.
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APRIL 2005