You've pretty much summed it up.

It's managment speak for things like kanban, kaizen, Just In Time and the like.

Don't get me wrong, there can be little gems hidden in all the consultant BS but basically it is about minimizing waste/maximizing efficiency.

For example, where I currently work by 'lean' they basically mean that rather than building a sub-assy and then booking it into stores you instead buid a sub-assy then put it on/in the relevant production line shelf/bin for use in the next stage of the pseudo assembly line.

Well they have gotten rid of all the drafters / designers so that project and design engineers have to do all that work, and all the admins so that project and design engineers have to do that work as well, is that "lean engineering"?

Regards

Mike

So long as they've got rid of any checking function too, and preferably everything's MBD with no consideration of tolerances permissable and hopefully the document control process is more flexible than a young female eastern european gymnast, then yeah, you're lean.

My comment was going to be along the lines of Mike's but a question came up as to what does it really mean.  Would Lean Engineering be designing products more efficiently so that there is less waste or efficiently designing products so that the engineering workflow is efficient?

KENAT, the checking function still exists, you just check your own work. Document control process demands flexiblilty from the users, not the other way around.

NomLaser, obviously, the path to lean engineering involves knowing just exactly what is to be designed and how, exactly what problems are to be solved and how, before ever starting so that all that wasteful iterative effort is avoided ;)

Is it Monday yet? Yeah.

Regards,

Mike

"KENAT, the checking function still exists, you just check your own work." so that's a "yes they got rid of the checking function".

Not permitted to issue unchecked work. Therefore, the checking function exists.

Regards,

Mike

I'm waiting for the trend of "lean manufacturing", "lean engineering" to progress to the next level - - - "lean management". Then, I think productivity will truly increase.


Most of what we call management consists of making it difficult for people to get their work done. - Peter Drucker

 

Sounds like lots of unpaid overtime, no coffie breaks, and reduced pay.

We used 'lean thinking' for a few years. It was a fad of management for a while until they got bored with it. Generally the riff raff ignored it but it kept management in meetings and off the streets for a long while. For those who are yet to begin this new mantra of thinking; prepare your paper clips to be neatly arranged!  

corus

I remember taking a course about 10 years ago in lean manufacturing.  I was in engineering at the time, but could not believe someone that works in manufacturing would look at it as a good thing.  We got to watch a video of a plant that had incorporated lean principles into their manufacturing process.  Apparently it saved so much time that the workers got to sit around the last hour or two of the day and work out how else they could improve things etc.  Unless they were union, I guarantee they would start laying off workers if they were under capacity like that.

Have never heard of Lean engineering.  But I am sure I have experienced it ;)  I agree with a lot of the others.  It could even just involve designing more modular components, wearing multiple hats etc.

In the end it is bad for everyone.  I would rather my company be able to design a different junction box for every vehicle line just to keep more workers employed both in engineering and manufacturing.  But those days are long gone.

Much of the lean ideas are little more than common sense. For example it makes a great deal of sense to not carry stock, if you can get the raw materials in as you need them and get the finished article out the door the same day, with the right credit terms you can actually make money. This is fantastic right up to the point your transport breaks down, gets snowed in etc and you are on a huge penalty clause for arriving late with the parts.

As with most things in life a compromise usually offers the best solution. But that does not mean that companies should not strive to be more efficient or people in smart suits should not "earn" loads of money for chucking buzz words around.
 

lean engineering = more accidents; why ? 'cause you're actively trimming "fat", untill you start to trim bone (by mistake).

it's easy to figure out the cost of bad engineering, it's very hard to put a value on good engineering ... an "optimum" structure doesn't tolerant off-design conditions well and doesn't allow for future growth (increasing load capacity).  a robust design does these things.

and what is efficient engineering ?  trying to make the best product for the least cost.  so, we try to get ahead of the curve, see what materila we've got available, talk to the "plant life" about how they'd want to make something (bent up or machined), go down that path only to change Everything 'cause the manu. mgr wants to offload to a water jet fabricator ... sigh.  is it efficient to make a weight efficient structure that costs a bunch to make ?  (clearly) no, so where the thing's being manufactured factors into the design decisions, and that can change at the drop of a hat.

is it Friday yet ?

I agree with Ajack on the having inventory of stock materials. Good in theory, but in a practical world there are issues, and a compromise is best.

One aspect I would consider "lean engineering" would be to make parts symetrical so that they can be used in multiple places. In some cases where I'm at, we had "left-hand" and "right-hand" versions of the same part. They were easy enough to tweak to make them the same. Makes life a little easier if you are stocking one part instead of two, don't need to try to differentiate at assembly, etc.

Another aspect might be bolt sizes. I've seen many engineers go through a design and size the bolts appropriately. However, in some cases they specify an assembly to require (28) 1/2" X 3" Bolts and (14) 5/8" X 3 1/4" Bolts. To me, if the larger bolts will work all the way around, it's better to just use (42) 5/8" x 3 1/4" bolts. Less bins to pull hardware from, easier to find the right pieces at assembly, easier for drafting (all holes same size), easier to manufacture, etc...

However, I'm not sure these are the concepts meant by others when they say "lean engineering." In fact, many places may tend towards trying to use the smallest and cheapest bolts and such to minimize cost. Of course, then they wonder why it's taking 10% longer to assemble or complain about some field assembler that mixed up bolts that differ by 1/4" length and have to go back and remove bolts that were already installed.

Obviously, some companies/people are more careful, more organized, etc that can make the issues about grabbing hardware from different bins, getting the right items at assembly, etc less of an issue. However, I still wonder if the little bit of extra time and thought it takes is justified by the $0.02 savings per screw.

Sorry for the rant...

-- MechEng2005

A lot of things can get hidden in "lean" manufacturing as well.  You might trade one visible cost for one that doesn't go directly against the books.  It really is a bunch of mumbo jumbo, and I have an industrial engineering degree to back that statement.

If you do things right the first time, and have enough time to properly test and prototype then you truly are "lean" on most respects.  Since most companies can't even give that time.

James Spisich
Design Engineer, CSWP

back to the OP status as a process engineer.  It means the use of more standard things.  If you need a 67.5 gpm amine unit, buy a stock 75 gpm unit.  If the process calss for a 1250 HP compressor and they only make a 1230 or 1400, tweek the process to use the smaller and just show the offset design or ask if they would like better than spec if you used the 1400 HP unit.

Minimize spares or use two 75% units versus 2 100% units.

beaware of the cost benefit ratios as you do the design.  Will a .2% under design that saves millions be worth the added cost.

So much depends on what numbers are being produced as MechEng2005 says

Obviously, some companies/people are more careful, more organized, etc that can make the issues about grabbing hardware from different bins, getting the right items at assembly, etc less of an issue. However, I still wonder if the little bit of extra time and thought it takes is justified by the $0.02 savings per screw.

Well if you produce 100,000 vehicles a year with a five year run and 100 screws in every vehicle saving $0.02 per screw gives a total saving of $1,000,000 that has got to be worth a little bit extra of anyone's time. If you can reduce the part cost of every component in the vehicle the savings are simply huge.
 

You are right in some cases. In other cases there really isn't much penalty for having a custom design for particular application.

An example is alloy wheels. The tools are expensive and bulky. So wouldn't it be a great cost saving to use the same wheels on two different cars?

No.

The tools have to be completely refurbished, which takes 6 weeks, after so many cycles (of the order of 10000 wheels, ie 2-3000 cars, or say one or two weeks production), so if you are making twice as many of one design, you need twice as many tools.

In fact the main cost of an alloy wheel is the metal (by a huge margin), so if you can design a lighter wheel for the lighter vehicle, it might even be cheaper, in addition to whatever marketing advantage you get from unique wheel designs. Of course there is extra up-front validation work required on two wheels instead of one, and there is a stocking cost in the assembly plant.

 

Cheers

Greg Locock

SIG:Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.

The term "lean engineering" to me conjures up images of carrying minimal permanent staff, using contract labour to fill gaps.

- Steve

my business' opinion of staff/contractors goes in cycles.

sometimes its "permies good, contractors bad" ... permies are perceived to have more interest in the company, will make better long term decisions, not just interested in how many hours they can scribble down on their timesheet this week, nor would they jump ship at the drop of a hat for an extra $1/hr.

other times it's the opposite ... contractors are a skilled flexible workforce that can be tuned to the work load, permies are inexperienced (and thus too brave or not brave enough), too slow to react to changes, unwilling to reach outside the box.

Good point Ajack, the quantity definately makes a difference. In cases of assembly line mass production, it might still make sense to keep screw sizes consistant for each stage of the assembly. I certainly would not expect to see the same size bolt holding my wheels on as the bolts holding the hinges on the glove box. However, if the same size screw could be used at each stage (i.e. all exhaust pipe clamps are the same), there might be a benefit. There might not be.

To me, the concept of "lean engineering" would be to understand the whole process from first concept to shipping it out the door and warranty issues, and basing the design on what works best throughout the process.

Personally, I feel that "lean engineering" is just some jargon for what has been expected of engineers/designers for a long time. Just some new buzz words to "repackage" an idea that's been around forever to sell it to management.

-- MechEng2005

So all the to my understanding all the talks of using one type of screw etc. would be covered by DFMA (Design For Manufacture & Assembly), which is another buzz word (or I suppose Acronym).

What gets me about my current place is they seem to want to apply principles based on production rates/quantities similar to mainstream automotive when our actual run rate is more like Morgan or Ferrari.

Sure, we could spend hours fine tuning these things, $1000's on tooling fixtures, man weeks spent creating step by step assy procedure etc. but when we only build maybe 5 a month of any particular product, with maybe a product life of 5 years are we really recouping our investment?  Or would we be better off having slightly more highly skilled shop floor staff that can work without these aids, freeing engineering up to design the next new product and beat our competitors to the market?  Of course, given the way we (don't) track engineering time and amortize tooling costs etc. we may never know.

"Lean engineering" means increasing the ratio of engineering work to engineers.

My office is currently attempting to practice lean engineering as it lays off more and more engineers. Of course, the engineering work load has dropped as projects fail to materialize. Sometimes it seems like it is simply a matter of time before the value of lean engineering approaches either infinity or an indeterminate state.

xnuke
"Live and act within the limit of your knowledge and keep expanding it to the limit of your life." Ayn Rand, Atlas Shrugged.
Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.

Are you leaning the processes that work or the processes that are broken?

It's my experience the processes owned by the politically weak targets are the ones leaned. Politically unassailable divisions that cannot be looked at with a critical eye are spared the exercise.

We had a politically strong group conducting exercises to lean error correcting processes. At the same time, we couldn't get resources to develop tools to support core functions to keep us from making the errors to begin with.

I do support improvement, sometimes the packaging and motivational stuff gets to be a bit much.

Make it look good whatever you do.