I have never impressed management by demonstrating how many hours are lost, as long as the project completed (more or less) on time. As long as those hours got squeezed into the schedule somehow, good enough. Even when I was contracting (and paid big-$ overtime), management didn't appreciate my ROI calculations on a second monitor (less than a week ;).
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That can be changed in a jiffy. On my first job the company (initially) thought that marketeers were more important than engineers. We had three CAD stations and since we needed those a lot that meant some night work. One day when I saw yet another marketeer writing some sales letter during the day on one station I had it. Went to the director of engineering and told him that I will not come in at night anymore, starting today, and that the schedule I signed would not be honored unless there are no more marketeers down in that room. And that they should spend less on perks and buy their own PC instead. Alternatively they could go to the back of the line, pick a number and come in at
3:00am. It took about two minutes and the problem was solved :-)Despite all that I later dated a gal from the same marketing department, she is now my wife ...
Sometimes they should look, they'd be surprised how much lower in cost projects can come in with external engineers.
-- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
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One job I had, we had to do 3rd shift to get test system time. I usually found better things to do than run test systems (what a crap job), but one Christmas the fickle finger of fate pointed my direction. One 3:00AM to
8:00AM shift was enough for me. I told my boss that when the problem got enough attention to get me 1st shift time, I'd work on it again. 1st shift was taken by manufacturing. The real problem was that *every* Intel part failed incoming inspection. They had sent us everything with legs to make their year-end numbers. They got it all back and the parts were much better in January.Paybacks. ;-)
Just add up the cost hiring of employees. The down side is that sometimes contractors with the appropriate experience are hard to find, particularly ones willing to work on-site.
[...]
Yes, they are often hard to find. But they can be more loyal than employees. If an employee quits after a number of years he's gone. He can't be there for you even if he wanted to because he's got a new fulltime job, plus a family, and so on.. A consultant or contractor can usually be called in again. I had clients from the early 90's who called me in on a problem 15 years later. The fact that I have moved across an ocean in the meantime didn't matter, if you want to be found you can and will be found by them (I gave all of them my new address, just in case).
On-site, yep, that can be a problem. But when one thinks hard about it, how many times is that really really necessary? Most of the time clients just send me the whole chebang to diagnose in my own lab. Other times I fly out there for a few days. Sometimes it's a long trip, like one to Korea but that was necessary because I needed to train their engineers so that the EMI problems they had wouldn't happen again on their next design.
-- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
Consultants are more loyal because they can be bought. ;-) Employees really want to be part of the family. They're going to live there, they might as well be.
Tell that to managers. They like to think they're in control. They like to think having someone on site puts them in control. I suppose if you don't trust the person, at least you can make sure they put in the hours. Conversely, being off-site can have its problems, too. The big-picture can be missed, or expectations can be completely unrealistic.
Hi Keith,
Yeah, that's what we presently do as well... the part numbers are long enough that you'd end up with rather cluttered schematics if they were always on, although I suppose some places might have them on by default and then have the guy drawing the schematic just turn them off for individual components in areas that too become too dense.
We can't add (or modify) parts, but otherwise we do the same thing.
Yes, I'd accept that he had too many tasks to perform that were more company business-critical than fixing parts libraries. However, I don't see any good excuse for why he'd make that claim while simultaneously refusing to allow some of the engineers to go and clean things up (and they had volunteered to do so). Management eventually leaned on him, telling him he either had to start fixing errors in a timely manner or allow other to do so in his stead, and since he didn't like either of those options, he chose to quite instead.
---Joel
That would be everywhere. ;-)
There are only three of us likely to add components, but it's just cleaner if one does it. I don't like the way others draw components so I do my own, even if it already exists.
Sounds more like it was a power trip for him. You don't need control freaks around.
OK, I just finished (or at least got working) BLUE.EXE. It compares the parts in a PADS-Logic netlist to our MAX parts/inventory database.
It checks that each PADS part on the board has the required attribute fields. A part entry in the PADS-Logic netlist file looks like
PART C50 { "ORIG" JL 7-24-96 "DESC" 0603 SURFACE MOUNT CAPACITOR "HTI" 103-2720 "VALUE" 0.33uF }
Where HTI is our in-house MAX stock number. Pretty ugly, no? PITA to parse.
The program verifies that the DESC, HTI, and VALUE fields are present and look about right, then verifies that the corresponding MAX part actually exists, then verifies the value and package types against what MAX expects. I only process R/L/C parts, since they are the ones that cause the most trouble.
It's done in PowerBasic in the clumsiest way possible... tons of string operations, linear search of all MAX parts for every PADS part, gross stuff like that. Analysis of a 1200 part VME board runs in 0.156 seconds.
Parsing and comparing the values was a little tricky. 0.33uF was not exactly the same as 330nF in floating point, and some people decided that m was milli but M was mega. Sometimes.
And things like "1206" can appear in various places in the DESC field for some PADS parts, like resistor networks. And so on.
560 line source file, 38 kbytes compiled.PINK.EXE was the one that compares two PADS-Logic or PADS-PCB netlists.
John
Having the attribute names in quotes but the attribute values not in quotes sure is a pain...
I was wondering if you were going to deal with this...
I've often felt a tool that goes around and "standardizes" all the decoupling caps to 100nF or 0.1uF or whatever one prefers would be useful. Not because I'm a nazi when it comes to suggesting that there should be hard rules for when fractional values are OK or not (although some people around here are...), but rather because I think there's value in having consistentcy in your schematic: 100nF vs. 0.1uF vs. 0u1 (ouch!) tends to just say something about how old you are (when you went to school) or if you're in the U.S. or Europe, but different styles throughout the schematic makes you look schizophrenic, which is rather more worrisome.
I once had a "helpful" tech decide that my 22milliohm current-sensing shunt resistor (labeled "22m" on the schematic) was really 22megaohms. The circuit didn't really work after he made that substitution... :-)
I take it your program elicits some warnings if it's trying to be "smart" and discoveres that m/M confusion likely exists?
Sounds pretty useful; very neat!
For some real fun you should write up a description of the program and see how much a professional software developer would want to code it up. :-)
---Joel
Often schematics are assembled by cut-and-paste from other schematics. Then the bypasses do look schitzoid. I use 0.33uF 0603 as my standard bypass, but the kids have decreed that it should be "330nF"
We do try to minimize the different parts on a board to simplify pulling kits and assembling boards. 100R, 1K, 10K, like that.
It wouldn't be hard to pile up a *lot* of microfarads of bypass caps on one plane, scattered over many sheets of schematic. Enough to freak out some LDOs that, on the power supply page, have an aluminum or tantalum bypass.
No, I'm figuring it will eventually throw a mismatch as a warning. The m/M case is rare anyhow.
John
Have one of the kids write up a PowerBASIC program (or whatever their programming language of choice is) to find all the capacitors connected to a given net and add up their values? :-) That'd be a kinda cool macro, actually...
We just skip nF completely. The only question is whether it's .001 (uF assumed), or 1000pF. I guess even that ends up dependent on where it's used. Decoupling it's .001 and in a filter it's 1000pF. Yes, a mess.
This is an area where I think those newly minted graduates do bring something of value to older engineers -- they don't shun nF. :-)
We don't have any particularly hard and fast rules, but in general all capacitors and inductors get their full units spelled out (22nH, 100pF, etc.), whereas resistors don't have "ohms" added *unless they're 1-999 ohms* and hence would otherwise have no suffix at all. This is a sort of compromise between "ohms" spelled out looking a little dorky since ORCAD won't let you use a proper Omega symbol but still wanting at least something to suggest you didn't just forget a "k" or "M".
I am guilty of doing dumb things like having just labeled a bunch of inductor in nH and then proceeding to label a bypass cap as 100nH rather than 100nF. Oops...
When we first started implementing our new MRP system some years ago now I made the suggestion that, when searching for parts, It Would Be Nice to have the system be smart enough to understand the standard metric suffixes so that when someone creates a part that's 100nF it can still be found whether someone searches for 0.1uF, 100nF, 100000pF, 1e-9F, or any other silly combination you might think up.
I'm not expecting anything that useful will actually end up being available (I'm not at all impressed with the flexibility of these big MRP systems -- seems like many of them aren't much better today that what existed 30 years ago), but I'm crossing my fingers that someday I'll be pleasantly surprised.
---Joel
I didn't either. In fact the hybrid I first worked on was all in nF because all the caps were in that range. They don't so I stopped. I don't really care, nF is easily enough covered by uF and pF.
We could, but there are more significant digits in resistor values and the vast majority of resistors are in the 1K to 1M range. I significant percentage are 10K. ;-)
I could argue that you should be using mF, too, to be consistent. ;-)
See, you wouldn't make that mistake if you labeled them ".1". ;-)
Amen! As it is, I do this in a Excel spreadsheet but it's a PITA. The parts system should take care of that administrivia. That's what computers (are supposed to) do. As I'm told, our system was quite expensive, yet one couldn't design a much worse UI on purpose.
Why would you even hope for sanity? It's just something to live with.
We have standardized on pF, nF, uF, and, sadly, mF. Numbers are never below 1, except 0.5 pF maybe, and never start with a decimal point.
Resistors are 12R, 3.01K, 22M, 3G, 1T. I suppose I'd parse 14mR or just 14m as 14 milliohms. "12" will parse as 12 ohms. We will NEVER use the juvenile 4k7 thing. I'll enforce that in my will.
Hmmm, maybe I should parse 2.2F properly, in case we buy some supercaps some day; I'm not doing that now. One more line of code.
We are all shocked, shocked.
It is fun when you ECO replace a resistor, like R99, on a board with a capacitor, which has to still be R99. I wonder what my crosschecker would do in that case.
All our resistors and caps are... believe it or not... IN ORDER BY VALUE. That makes shopping for parts really nice. I also have a program that finds resistors in stock that approximate desired ratios.
John
...and have double sourced and have confirmed footprints!
Nial.
Yeah, but when an employee quits that's usually like a divorce. He or she is gone. I just had that happen with a company where one of their key engineers on the project quit and it did cause noticeable project delays.
That's why consultants must be great communicators and generalists. "What happens if the signal at port B doesn't .." ... "Oh, dang!"
-- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
Yeah, mF does seem a little odd to me, but I can't think of any good reason why it should be, so at least when I'm thinking about it that's what I use.
Although there aren't that many caess where I have a capacitor that's 1mF or more anyway -- these days switchers are so fast you don't normally need them. I suppose there's still SuperCaps...
I'm happy to label things fF -- probably just due to the IC design class I took in school (effectively "op amp design exactly as been's taught for the past 50+ years, we've just made now the transistors really, really small"), where almost everything was inbetween 1 and 999fF, so it became very commonplace.
On occasion I'll get to label something as pH as well (almost always just within a simulator, though -- e.g., shorted or open microstrip stubs; on the schematic these get turned into dimensions).
Really old schematics that label things mmF are kinda cute.
That sounds like an entirely agreeable system. "R" perhaps is a bit better than "ohm" (...but if the CAD tools would let you use an Omega, that'd be better still...).
:-) I don't blame you -- 4k7 is meant to solve a problem that largely doesn't really exist anymore (lost decimal places on tiny/xeroxed printouts).
Is that because you wrote a smart sorting routine that understands metric suffixes? Or because internally you store the raw value so sorting is trivial (e.g., 100nF is stored internally as 100e-9).
---Joel
"Nial Stewart" wrote in message news: snipped-for-privacy@mid.individual.net...
Your purchasing peoples' lives will surely become way too boring if you don't strive to single-source as many parts as possible.
:-)
Just kidding, double-sourcing is of course great when it's an option.
I've seen it both ways... I guess it comes down to both what the engineer and the company expect, and this is often the kind of thing that isn't ever written or formally verbalized: Some companies seem to take an engineer quitting as a form of betrayal and will start bad-mouthing his work and not want any contact and effectively blacklist him from being hired again, whereas other companies figure that if an engineer wants to check out whether or not the grass is greener elsewhere, if he does so during a lull between projects so that there isn't any huge disruption and stresses that he's happy to have people call him to ask for support on some old project he did, there's no need for bad feelings and the perhaps the guy will be invited to come back if the new place doesn't work out.
The later might happen more in non-technical businesses, perhaps? -- My wife still does a few little side-projects for several of the places that she's previously worked for.
---Joel
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