design,production: new product

[paulpaul]

good day to all I am a student of mechanical ing,
I wanted to open a general discussion about a "problem" regarding the production of a new product.
reducing the stages to the bone, we could say:
the design department delivers to the production the engineering of the product (models cad, etc.). at this point the production department defines the various technological cycles, times and methods to send the new product into production (magari on a pilot line).
before the product enters production line in a definitive way, it often returns to the design stage to solve problems that occur in the production phase.

what I ask at this point, referring to your practical experience on the field:
What are the most recurring motivations of these "loop-backs"?

in an optimisation of times, I wonder (always with the support of those who live these things every day): Is there any information that one department or the other would already want to own to not have to resort to the project?

a chat that is sometimes so bad to give me a more precise idea about the major criticalities:biggrin:

thanks to all and good work

Edoardo

Hi.

I briefly illustrate my experience in the company that works in the oil & gas sector: the product is a "compressor system", formed by a machine (compressor) and a plant (piping, pressure vessels, frames, valves, tools, etc.), both internal design. machine details (99.9% drawing or specification) are manufactured externally and assembled internally.
the details of the plant are mainly commercial from catalog (50%) to design (25%) and commercial to specific (25%), with variable percentages depending on the complexity of the plant.
revisions can be in practice of two types:

1) related to a specific order

2) general "product"

the first can occur in one of the following stages:

1) phase of supply, in which the customer asks for plant changes (the machine is selected by composing different bricks and normally the customer does not pay us) before freezing the version that will have to be offered: revisions to p&id and ga, which however retain the character "preliminary". This phase is conducted by the "application" sector, which is the head of commercial (but with experience in ut), with the direct help of the technical office only in the case of particularly complex projects;

2) post-order phase, in which ut dialogues with the customer to arrive at the afc drawings (approved for construction): still revisions to p&id and ga, but in this case we talk about potentially executive designs.

3) frozen the afc version, you make the drawings of the non-commercial details (mainly piping and carpentry if the machine is "standard" otherwise also of machine parts), you emit the specifications for the other details or you choose directly from catalog, you end the dibas and load to mrp. purchase orders start.

4) at this point revisions can be requested by the customer (they are complied with and possibly agreed for a slip of delivery) or by the purchasing office (suppliers): The latter case is mainly dictated by cheaper alternatives available, too long deliveries for other commercial details and cost motives on drawing parts, on which the supplier asks for changes. if approved internally, they propose to the customer for approval and in case the afc drawings are reviewed.

5) arrival of the materials and start mounting. here the real pains begin with production, since there is no project in which production is not complained. the designer's task is to listen to everyone to try to understand whether the motivations that push to replace/modify a particular are founded or not. in case you make further revision of the afc.

6) with the functional testing of the system, changes may be required to "adjust" the performance and/or changes to the management sw. you do at this point the as built, with backward changes on the dibas. these are the latest drawings/diba products for the order, information that will also end in manuals.

if we talk about general changes instead we identify the following causes:

1) reliability/security problem: typically decision on service indication;

2) performance problem: autonomous decision or on indication of service, production (collaudo), commercial (after sales);

3) cost problem: decision ut on indication of the purchasing office

4) ergonomics/lead time/standardization problem: Decision on production indication

others could mention it and all can have different levels of urgency: from retroactive remediation (god free!) to exhaustion stocks in stock of the old rev.

reduction times? what I can say for my experience in a company where the product is central is mainly one thing: needs a shop manager and a technically competent production manager, preferably with experience in designing at least 5 years. In this way, delays are reduced to a minimum, and internal dialogues are more "free".
would serve, for example, that the office purchases, evaluated a design (by the way, can you read it?) choose the appropriate supplier. who knows how to interpret the specifications of a commercial component and how to involve alternative suppliers when necessary and that it does not constantly involve ut in endless analysis of specifications and to reduce itself to the pure formalization of orders.
needs a production that knows what materials to keep on stock or not, based on the product: and what components of the diba to anticipate and delay, to avoid engaging warehouse without having a benefit in manufacturing times (because maybe to go ahead with the assembly "serve something" that was not thought to be so "in advance").
of course it is also necessary to know that a piece cannot be realized in a certain way, or that a tube at that point will never pass.

then you can discuss transmission systems revisions (I am not very favorable to pdm...it will be my fix) but these above (and others) are essential requirements to reduce time. If there is a good dialogue between ut/production I believe that many problems can be solved without the help of particular sw...

Sorry about the gun! :

 

[yudansha]

Hi.

I briefly illustrate my experience in the company that works in the oil & gas sector:.....

Thank you very much for the answer, very exhaustive.

I want to ask you again: in your experience (in reference to the pieces you produce internally) it has never happened that production complained of a choice material made by theut, why would it lead to higher production times?
(...instead maybe choosing for that component another material the technological cycle would have been a little faster)

 

[paulpaul]

Thank you very much for the answer, very exhaustive.

I want to ask you again: in your experience (in reference to the pieces you produce internally) it has never happened that production complained of a choice material made by theut, why would it lead to higher production times?
(...instead maybe choosing for that component another material the technological cycle would have been a little faster)

Look...the only pieces manufactured internally are small carpenters (rarely) and welded piping. for the first the material is always a s235 or similar, for the second it is mainly about two materials: Carbon steel or stainless steel, with different designations depending on the standard used (but with mechanical characteristics substantially equivalent). the choice of one or another depends either on the process or on a specific request of the customer, ut is quite obliged in this.
I would say that this kind of observation I have never heard of it! :smile:

 

[numero1]

But I think it didn't happen. .
it is said that in the equestrian monuments the position of the front legs of the horse says how the knight died
if both legs are lifted, the knight died in battle
if only one leg is lifted, the rider was wounded and died after
if the legs are all on the ground, the knight died for other causes

not knowing how to die... I will predict all the hypotheses

Of course I know the history of the number of the legs, it's just that I didn't think you were referring to that. :biggrin:
So even the dog of the bar was designed to predict all the hypotheses or was it just an error?
I already know the answer, I guess you know it too.
Hi.

 

[numero1]

They're state secrets that in comparison to Ufo files are like jokes at the bar.

+

This happens to me often and willingly, I have clashed myself several times with the bosses saying that when the machines mounts the guy would want the tolerances to be of one type and when he mounts another. I said that if they want to make a double or triple set of identical designs customised according to the editor, but they have to decide a priori before the production who will mount the machine.
not to mention the revisions... in 2007 project a structure of a machine not just trivial, end project/production I get some changes to perform/forature to add/ecc. I do so review 1. a few months later they launch the same machine into production, it is performed with rev.1 , changes the editor... you get to rev.2 . I am present at the high spheres that the "menates" that made me change non have no actual utility. nothing to do is run rev. 2 . a few months after even further production of the machine, this time in rev.2 , changes again the editor and "magie magic" further changes to do. you get to rev.3, cnc operators ask me if I'm taking them for the "culo", I tell them that I threw the sponge after revision 1 and that they arrange with the climbers and the boss.
well, we are at the end of 2012 and the project in question is to the revision 7, fortunately stable in the rankings from 1 year to stand part. for obvious reasons I cannot, but I would post the pdf of all the revisions made at least you make 4 laughs and you will notice that the revisions 2-4-6 have several holes that return to their place compared to the revisions 1-3-5.
For my part, I have responded that if they want to create a job, I thank them, but I can use my time better than to "size" paper for nothing.

I understand you very well:
thinks in my old company they invented variants......
the story:

I am asked to normalize the x product, or to verify that it is always produced with the same documents and that they are actually available + updated.
I clear myself, I do research in paper archive and on servers, I talk with how many + people possible (excluding workshop), and in the end I can get all the information necessary to do the agg.te revisions of every single piece of the component, in addition to the overall design.
made all and mold, step in workshop and comparison with meter and caliber and the assistance of the workshop head the paper drawings with the finished product.
Obviously it does not return to 100% there are things that lack others that are added, others that are moved etc. etc.
the workshop leader shows me with which designs they build the product today.
drawings that are a "sirty thing" a mix between the old and the last revisions..... :
I decide not to investigate further and, strong of the assignment entrusted to me by the technical director in person I say: "look that after integrating my drawings with what I found on the finished piece these will be the gospel."
I make mold, and I distribute a copy to all interested subjects by requisitioning (it is precisely the case of saying) all old paper formats.
and start the mess....... .

(end first part)

 

[numero1]

(second part)

"But here are not good valves......"
"thank you, I answer, we're going to the balls as a specific technique."
and many other things...... I let you imagine.

mega meeting and.......
in the end it turns out that the aqu office decided which components to buy on the basis of the price of the moment, of course the fin valve had characteristics different from the ball, e.g. of the different fixing holes.......
Wow, I think, that's why there were all those differences over the years.
we had a very creative workshop, but
but not only sometimes the warehouse was full of fin valves, but the customer wants the balls.
And so what do you do, but it's simple to shove the pins as a ball, it's obvious if it's okay we take a lot of stuff out of the warehouse; but if it's not okay...

the mega meeting is about to degenerate, but at this point the technical director (of fresh appointment and therefore had to show the muscles) says:
"This product is done so according to the latest documents produced by him (i.e. me)"
and then adds (unfortunately) "at most we can make the variations".

in practice the xyz rev. 4 design could exist in variant a for the fin valves and in variant b for the ball valves.
easy not......
and this for almost every single component of the thermostat product, gauges etc. ..... That's nice.

a beastly casino of management, but feasible, if there is one like me that keeps keeping the archive updated obsessively.
If in fact the xyz design passes from rev. 4 to 5 it must also check that this does not interfere with both types of valves used.
and then bring out Rev. 5 in 2 variants, or 3 if there is also c, d, e .... etc. etc.

has advantages this ....
Yes, you have a product always agg.to and fluid that adapts to every situation while remaining the same and doing the same.

the disadvantages are that it is not a normalized product, depending on what will be decided to buy there will be processing differences.
production therefore will not be controllable....
And then what do we put in the catalogues?
"but sorry the total size is equal"
"certain overall dimensions have always remained equal we would miss, and this until revision 0"
"then it is made, we can advertise in the catalogs our internal diversity of the product. "
in practice has become a strength......... .

and that's all, I managed to carry out the situation until I was in there then.......... .
then it turns out that since no one wanted to take the brigade of agg.re that parallel archive that I had been forced to create, that with the variants to understand, the situation has remained frozen.
in practice nobody wants to change or update + nothing for fear of messing up.
where, instead, a revision in + could also be healthy, subject to the due checks.

 

[numero1]

by the way, if you think it's an isolated case, try reading here:http://www.cad3d.it/forum1/showthread.php?t=25107&page=9post #88 and #89

a description actually much more picturesque and made better than mine. Too bad the guy disappeared.

great flatsix, :smile: yes it is a sin that has disappeared.
Hi.

 

[MBT]

Thank you very much for the answer, very exhaustive.

I want to ask you again: in your experience (in reference to the pieces you produce internally) it has never happened that production complained of a choice material made by theut, why would it lead to higher production times?
(...instead maybe choosing for that component another material the technological cycle would have been a little faster)

to me yes, regularly!

great flatsix, :smile: yes it is a sin that has disappeared.
Hi.

già... :frown:

 

[Fulvio Romano]

a beastly casino of management, but feasible, if there is one like me that keeps keeping the archive updated obsessively.

management of variance... This stranger.

I do not know the specific problem.
the purchasing office has the specific problem of having the valves pinco and those ball. is a real problem, and not a fism; their purpose is to buy at the lower price, remaining not to complicate excessively life to others. If the piece that supports the valve had both the pinholes, and the ball holes, it would be fine in both cases.

variance should be managed in this way, of course where this is possible. otherwise the choice of the fin valve becomes a must. In fact, in general, the requirements are of type must, need e want.

if double drilling is not possible, the two variants are made. the valve requirement becomes a need.
if, again, you can double drilling, but for a reason any technical office continues to prefer pinco, will be a requirement want.

Finally, if there is double drilling and theut has no preferences, the valve brand is no longer a requirement, but only its presence remains.

 

[maxopus]

kill what's coming out of it.

 

[PierArg]

Thank you very much for the answer, very exhaustive.

I want to ask you again: in your experience (in reference to the pieces you produce internally) it has never happened that production complained of a choice material made by theut, why would it lead to higher production times?
(...instead maybe choosing for that component another material the technological cycle would have been a little faster)

right today :tongue:...even if not for issues of cycles but costs

 

[MBT]

right today :tongue:...even if not for issues of cycles but costs

Of course. . .
always for question of costs:frown:

 

[Fulvio Romano]

Of course. . .
always for question of costs:frown:

About materials, we are now ot.
I heard that there are those who, to save on the material, do long aluminum electrical cables instead of copper...

someone knows something about it, although there are 64/8 says that the conductors must be copper.. .

 

[yudansha]

to me yes, regularly!



Yeah...

azz.. and motivate? that is, in particular, you get:

 

[marcofor]

About materials, we are now ot.
I heard that there are those who, to save on the material, do long aluminum electrical cables instead of copper...

someone knows something about it, although there are 64/8 says that the conductors must be copper.. .

the cables of aluminum electroducts with steel core are realized how much weight and cost saving is beneficial, even if you lose something as aluminum has a greater resistance than copper.

 

[MBT]

azz.. and motivate? that is, in particular, you get:

ah, simple.. .
call from the shopping office:"yes... oh... so... I have this design, no.... the supplier tells me that to do it with the material you indicated costs a bang and it is 6 weeks to find the material! Look, the guy here tells me he could do it in 25burroricotta6 which costs less... You okay? "
"eh... caxxo... Let me see the design and application. ...
"No, no, I need to know right away... I have the online supplier who is cutting the pieces!"
":angry: but porc.. you and your @#§£ supplier... ♪the rest of the call is censored by decency:mixed:

 

[Tequila]

ah, simple.. .
call from the shopping office:"yes... oh... so... I have this design, no.... the supplier tells me to do it with the material you have indicated costa un botto e is 6 weeks to find the materialLook, the guy here tells me he could do it in 25burroricotta6 which costs less... You okay? "
"eh... caxxo... Let me see the design and application. ...
"No, no, I need to know right away... I have the supplier online who is cutting the pieces!"
":angry: but porc.. you and your @#§£ supplier... ♪the rest of the call is censored by decency:mixed:

but why does it happen to me that they ask you to change material because they give us a life to find it and then they tell you that they need to know immediately why they are already cutting the crudes?? ? ?

mah !!! strange mysteries in a few days we will also discover another truth (21-12-2012 :mixed

 

[MBT]

but why does it happen to me that they ask you to change material because they give us a life to find it and then they tell you that they need to know immediately why they are already cutting the crudes?? ? ?

but above all... .
Why do they always propose kurac steels that are worthwhile?
Why don't they ever tell you "you put c40 but I'd like to do it in 36nicrmo4"?
why delivery times are always long for them and never for you?
Why is the responsibility of the material change yours and the ability to reduce prices is of the purchasing office?
Why does he need the answer right away when you ask a question need at least three weeks to tell you that they don't know what to say?

will we have these answers on 22/12/12?? ?

 

[numero1]

I spoke of valves but only as an example, there were not only them:tongue:

management of variance... This stranger.

I do not know the specific problem.
the purchasing office has the specific problem of having the valves pinco and those ball.
No!
as they saw it, it was a problem...
leave some stuff in stock ok, leave a lot of stuff in stock no! horror ...... .
This is because, often the worker needed, and asked for a pressure gauge to be mounted e.g., and the storekeeper gave it to him quickly, without asking what he was giving him, he only marked.
so after a few months all wika manometers had disappeared.... .
aaaaaaahhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh
Where are they now?
around the world... so he was trying to have the warehouse always with little stuff, just to swab the emergencies and then buy some shit when he came or was about to get the contract.
I have personally seen people from the office aqu that + times came down to the warehouse to check that there was still their stuff from their store.is a real problem, and not a fism; their purpose is to buy at the lower price, remaining not to complicate excessively life to others. If the piece that supports the valve had both the pinholes, and the ball holes, it would be fine in both cases.
Yes..... true, but as the workshop worked the sheet from scratch, at the time of making the holes it only did those for the valves or gauges present in that shop.variance should be managed in this way, of course where this is possible. otherwise the choice of the fin valve becomes a must. In fact, in general, the requirements are of type must, need e want.

if double drilling is not possible, the two variants are made. the valve requirement becomes a need.
if, again, you can double drilling, but for a reason any technical office continues to prefer pinco, will be a requirement want.

Finally, if there is double drilling and theut has no preferences, the valve brand is no longer a requirement, but only its presence remains.

You've forgotten the customer... and so much to speak clear, if the customer wants atos valves, but you give him (or you want to give him) some oleostars you do?
or not?
What is a must, a need, a want?
Bye, go

 

[MBT]

You've forgotten the customer... and so much to speak clear, if the customer wants atos valves, but you give him (or you want to give him) some oleostars you do?
or not?
What is a must, a need, a want?
Bye, go

Aaaahhh, what a delight...
try to convince the rest of the band that has to buy the material of that brand (although it costs more) because it is in vendor list... :frown: