CAD: Quality, Productivity and Savings
Raul Nobre Martins
CAD: Quality, Productivity and Savings
I am interested in studies, comments, and ideas on what kind of
increase in productivity (if any) is achieved by using CAD and whether
such an increase in productivity results in any savings.
The last time that I checked, the common belief was that CAD was
contributing to an improvement in quality (one way of measuring
productivity) but not in terms of saving manpower (the bottom line for
many observers).
As I have never really seen any study on the subject, I do not know
how widespread is such analysis and - much less - whether it is
actually the case.
Any information or comments would be greatly appreciated. If you have
the time, please elaborate.
Thanks.
Raul Martins
**************************************************************
Raul Nobre Martins Illinois Institute of Technology - IIT
mar...@minna.iit.edu Chicago, Illinois USA
Phone: (312) 225-7595 Fax: (312) 225-9262
**************************************************************
Jeffory J. Beckers
Are you speaking of CAD in terms of hand drafting/design? If so, than I
can offer these words.
A good CAD operator cannot outdraw a GREAT hand drafsman on initial
designs.
A good CAD operator will blow away the GREAT hand draftsman on
revisions.
A great CAD operator will be much quicker than a great hand draftsman on
initial design.
As you say, the overall quality of a group cad department will improve.
Also, which CAD package you choose is important. Most people who have
had experience with both MicroStation 5.x and MicroStation 95 agree that
MicroStation 95 provides drafting tools which have a positive impact of
drafting efficiency. In fact, I would say that a good CAD operator,
properly trained in MicroStation 95, can outperform a great hand
draftsman on initial design.
------------ One of the people IN FRONT of MicroStation ----------------
Tri-Tech Imaging, Inc. Professional Computer Animation & Video Services
1555 Bustard Road P.O. Box 474 Kulpsville, PA 19443
Jeffory J. Beckers Production Manager jef...@tritech3d.com
World Wide Web: http://tritech3d.com
"Computer animation is not done by the computer any more than clay
animation is created by the clay." - J. Lasseter
Phil Chouinard [Bentley]
mar...@minna.iit.edu (Raul Nobre Martins) wrote:
>CAD: Quality, Productivity and Savings
>
>I am interested in studies, comments, and ideas on what kind of
>increase in productivity (if any) is achieved by using CAD and
>whether such an increase in productivity results in any savings.
[snip]
Raul: You might want to take a look at the KPMG Study regarding
something very much along these lines. A synopsis can be found on our
Web site at http://www.bentley.com/kpmg/. HTH
============== One of "The People Behind MicroStation" ==============
Phil Chouinard - ITO Phone: (610) 458-5000
Bentley Systems Fax: (610) 458-1060
690 Pennsylvania Drive CompuServe: 75300,3376
Exton, PA USA 19341-1136 mailto:Phil.Ch...@Bentley.com
== MicroStation FORUM & Exhibition @ http://www.bentley.com/forum/ ==
Elliot Johnson
Raul Nobre Martins wrote:
>
> CAD: Quality, Productivity and Savings
>
> I am interested in studies, comments, and ideas on what kind of
> increase in productivity (if any) is achieved by using CAD and whether
> such an increase in productivity results in any savings.
>
> contributing to an improvement in quality (one way of measuring
> productivity) but not in terms of saving manpower (the bottom line for
> many observers).
>
> As I have never really seen any study on the subject, I do not know
> how widespread is such analysis and - much less - whether it is
> actually the case.
>
> Any information or comments would be greatly appreciated. If you have
> the time, please elaborate.
>
> Thanks.
>
> Raul Martins
>
> **************************************************************
> Raul Nobre Martins Illinois Institute of Technology - IIT
> mar...@minna.iit.edu Chicago, Illinois USA
> Phone: (312) 225-7595 Fax: (312) 225-9262
> **************************************************************
Five years ago, when I first started working for Architects in the
Austin area, CAD had not become as widely acceptable as it is today.
The first firm I went to work for was a strictly custom design firm. We
did the initial layout on CAD, then finished the drawings by hand on
something like 50% of the projects we did, the other 50% were done by
hand. We had a custom menu that covered say 50% of the drawing process.
I equate this with having a T-square, but no drawing templates.
Originally, we spent anywhere from 200-600 hours per project. With a
little customization, and doing 100% of the drawings we were able to
reduce the time to 100+/- hours. Somewhere around this point the firm
became 100% convinced.s
The second firm was also not convinced of the merits of CAD, yet did 50%
by the computer and 50% by hand(mostly due to thier clients) This
company did mostly builder speculative architect. The typical projects
took around 40 hours by hand and 40 hours by computer. After a year and
a half of instituting a network, seven additional CAD stations, and
more custom menu programming, the firm saw its time frames averaging
around 24 hours, and now produces more than a 1000 plans a year via CAD.
With the third and final firm, a custom architecture firm, additional
programing, has reduced the time frames to 10-20 hours for a CUSTOM
project, and believe it or not, as little as 4 hours on spec projects..
So, you can see that CAD can provide the quality and advantages
everyone has heard of, and can totally blow hand drafting away in time
frames.
The most important thing is to use appropriate tools to do the job.
Every repetitive task that a team of draftspersons will be doing should
be automated to simplify the task, standards should be developed, block
libraries, lisp routines, base drawing sheets, SOP's should be
developed.
I hope you found this informative, if you have any further questions or
insight, please let me know. And, if I have offended anyone by this, it
is certainly not my intent.
Elliot Johnson
arch...@jumpnet.com
Ian A. White
>CAD: Quality, Productivity and Savings
>
>I am interested in studies, comments, and ideas on what kind of
>increase in productivity (if any) is achieved by using CAD and whether
>such an increase in productivity results in any savings.
>
>The last time that I checked, the common belief was that CAD was
>contributing to an improvement in quality (one way of measuring
>productivity) but not in terms of saving manpower (the bottom line for
>many observers).
>
>As I have never really seen any study on the subject, I do not know
>how widespread is such analysis and - much less - whether it is
>actually the case.
>
>Any information or comments would be greatly appreciated. If you have
>the time, please elaborate.
One of the great myths of the computer industry. This needs to be
qualified somewhat though ;-)
There are two areas here. One is the production draughting
environment, and the other is the design environment.
In the production draughting environment, there is very little time
saved in producing the initial drawing. Again here, this needs some
qualification.
With things like schematics, P&IDs, flow diagrams, yes, you will get
savings as long as you have the necessary symbols libraries. You can
realistically achieve improvements in productivity of anywhere up to
5:1 over conventional manual draughting.
With manufacturing drawings, the preparation of the initial drawing
will generally take as long as it would have done manually. The time
is in doing all the trims fillets, etc. These are things that never
required that much accuracy on the board, as you assumed many things
that the CAD program cannot and rightly so.
If you were to take an overall estimation on productivity on a typical
project mix of drawings, and remember you must also include the
computer related tasks of plotting, data backup, etc, there is little
difference between producing the CAD drawing initially and doing it
manually.
Where the savings come is in revisions, or where you can make use of
your growing databank of drawings. Rather than do it from scratch,
you may well be able to take an existing drawing, and with only minor
changes have a brand new drawing. Even if it is just revisions, you
can make substantial savings. I am in the process of updating a large
number of drawings I prepared for a client. The original drawings
were proposals, whereas they now have to be amended and made into
working drawings. Many of these have had as many as 6 major changes
in the space of 2 days. Had these been done manually, they would have
had to have been redrawn. Unfortunately, the ease of changing things
encourages changes.
The other thing to note is the operators. The proficiency of the
operator will have the greatest impact on any improvements in
productivity you might achieve. For example, I am able to prepare an
A0/B1 or A1 sheet of manufacturing details in approximately 8 hours,
so much so that I cap the average cost per drawing at this figure.
Any overruns are my problem. So far, things have always averaged out,
with savings passed on to my clients. So, you may have the fastest
computers with the most powerful CAD package, but poor operators will
put paid to any savings you are likely to make.
The other area is design. There are many applications which can
greatly assist in the design task, and this will impact on
productivity. The point of caution here is that there is not an
equivalent manual task to compare it with. Don't ever ask a
draughtsman or operator to estimate what something would have taken to
do manually. You will get widely differing answers depending on what
he/she believes you want to hear.
There is a great push to solids modelling, and it has its place.
Unfortunately I have also seen it as a source of waste. If your
machine shop cannot accept this model data, then it is simply an
additional task. Yes it CAN minimise errors, but again, I have seen
it as the cause of more. I was called out to a large toolmaker to put
forward a program to train their CAD operators. The company had just
had a rather aggressive salesman try and sell them a CAD system which
worked in full 3D, and would output the data directly to CNC machines.
The problem was that none of his machines could accept such data, and
to upgrade those with such a facility would have cost him a few
million dollars. He was simply not in a position to spend that
amount. As a result he went with LT, and now produces god quality
conventional drawings which his toolmakers can use with the existing
machine tools. He has seen small improvements in productivity in
production of drawings, however these were only seen once his databank
of drawings started to grow. On the quality side, there have been
less re-works because of problems with reading dimensions. There is a
consistency in drawings which makes it easier for the drawings to be
read on the 'shop floor.
So, yes, you can get productivity gains, and you definitely will get
quality gains. The problem is that there are many tasks which are now
done which were NEVER done manually. A good example is architectural
and model rendering. Sure these were done by commercial artists,
however because you had to get them in you used them sparingly. Now,
because your CAD program has the capability, you want to do it all the
time, not because it assists the design task, but because it looks
nice.
Anyway, now the fun starts.
Regards,
Ian A. White, CPEng
waiw...@zip.com.au
WAI Engineering
Sydney 2000
Australia
Chris Pollard
Ian A. White (waiw...@zip.com.au) wrote:
: With manufacturing drawings, the preparation of the initial drawing
: will generally take as long as it would have done manually. The time
: is in doing all the trims fillets, etc. These are things that never
: required that much accuracy on the board, as you assumed many things
: that the CAD program cannot and rightly so.
to be able to "draw". How can you draw a 3-D surface? I believe that it
is faster on complicated parts to do the drawing by computer because one
doesn't have to spend time figuring out hidden lines and intersections. I
believe I could redo my drawing exam faster with Pro/E than by doing it
with a pencil.
: If you were to take an overall estimation on productivity on a typical
: project mix of drawings, and remember you must also include the
: computer related tasks of plotting, data backup, etc, there is little
: difference between producing the CAD drawing initially and doing it
: manually.
some cases to do a fairly simple drawing - I can do a fully detailed
drawing and generate the necessary IGES files for machining in a few
minutes now for many parts.
: Where the savings come is in revisions, or where you can make use of
: your growing databank of drawings. Rather than do it from scratch,
: you may well be able to take an existing drawing, and with only minor
: changes have a brand new drawing. Even if it is just revisions, you
: can make substantial savings. I am in the process of updating a large
: number of drawings I prepared for a client. The original drawings
: were proposals, whereas they now have to be amended and made into
: working drawings. Many of these have had as many as 6 major changes
: in the space of 2 days. Had these been done manually, they would have
: had to have been redrawn. Unfortunately, the ease of changing things
: encourages changes.
job, much less time to make plastic tooling, much less money wpent on
tooling mods and the parts usually fit and work first time.
Ian A. White
On 12 Nov 1996 16:44:10 GMT, cpol...@csn.net (Chris Pollard) wrote:
>Ian A. White (waiw...@zip.com.au) wrote:
>: With manufacturing drawings, the preparation of the initial drawing
>: will generally take as long as it would have done manually. The time
>: is in doing all the trims fillets, etc. These are things that never
>: required that much accuracy on the board, as you assumed many things
>: that the CAD program cannot and rightly so.
>There are things that one can do on a CAD system that I would defy anybody
>to be able to "draw". How can you draw a 3-D surface? I believe that it
>is faster on complicated parts to do the drawing by computer because one
>doesn't have to spend time figuring out hidden lines and intersections. I
>believe I could redo my drawing exam faster with Pro/E than by doing it
>with a pencil.
You missed my point. When you have to convey this information using
conventional drawings to a workshop that cannot accept the CAD data,
most (if not all) 3D packages come up short. Take your example of
hidden lines. In a technical drawing, hidden lines are not hidden
from view, but simply displayed with a different linetype. I have yet
to come across a CAD program that will do this. Remember, that not
all of a line may be hidden in a particular view. Not showing the
line on a technical drawing can be very costly.
>: If you were to take an overall estimation on productivity on a typical
>: project mix of drawings, and remember you must also include the
>: computer related tasks of plotting, data backup, etc, there is little
>: difference between producing the CAD drawing initially and doing it
>: manually.
>It depends on the system you use. In Autocad it would take me days in
>some cases to do a fairly simple drawing - I can do a fully detailed
>drawing and generate the necessary IGES files for machining in a few
>minutes now for many parts.
Again, you are conveying IGES data. The point is that where a
conventional working drawing is required because machine tools cannot
accept CNC data, IGES, DXF, or whatever is useless.