Reasoning your way through the FSAE design process

[Mbirt]

Originally posted by flavorPacket:
After being beaten consistently by a girl 40 lb lighter than me, I couldn't agree more!

She's also Chrysler's plan to get those pentastar Challengers down on mass, right?

[Big Bird]

Thanks everyone for the input. I never intended for this thread to be a series of my monologues, so I certainly welcome any critique or comment you may have.

Kirk, very good point about drivers, and I tried to pre-empt a little back on page 1 in my "Potential vs Execution" piece.

To quote:

" Anyway, the argument I wish to make with all the above is that “Track Speed points” can be broken down even further into three interrelated factors:
• Design Potential: How the car will perform according to the calculations / lapsims that we’ve discussed earlier
• Vehicle Completeness: How effectively we deliver the designed vehicle to achieve its full potential.
• Driver Skill: How effectively the driver delivers the full performance of the vehicle
I’d combine the latter two factors under the term “execution”.

Now I’ve seen plenty of examples where all the focus was on the “design potential” side of things, but the final execution didn’t deliver on that potential. Examples include cars that don’t run properly on competition day, or drivers who obviously lack experience in the car. In our own team s I’ve seen examples where months were spent labouring over a couple of kgs (effectively a couple of points), but on competition day a swag of points gets lost because the acceleration event driver hasn’t driven the car before.

For most teams, the design potential of the vehicle may be worth around 0-20 points relative to your competition (and in many cases the decisions we are labouring over are maybe worth single points if that). Failure to complete the vehicle properly is a penalty of up to hundreds of points relative to your competition, and well trained drivers could be worth up towards 100 points. (I’m being a little vague as it depends on the team and where they are at – but certainly the penalties for poor execution are much more serious than the gains most of us are aiming for in our design stages). "

End quote.

Recently I've been focussing on the first aspect - understanding the design potential of the vehicle, because I see far too much emphasis placed on low points value measures (usually mass and power). My argument is that if we take our focus away from these little distractions we can dedicate more time / money / resources to the real priorities. And Kirk, you hit on a number of these, especially driver "comfort" with the controls.

I've got a piece coming about "designing for your driver", but that is taking some time while I compose my thoughts. I tend to take a bit of a contrary approach to a lot of the common motorsport axioms, especially when we apply them to FSAE. So I want to make sure I get the words right so I don't look more of a crackpot than I need to!

Cheers all,

[Bemo]

Originally posted by Big Bird:
For most teams, the design potential of the vehicle may be worth around 0-20 points relative to your competition (and in many cases the decisions we are labouring over are maybe worth single points if that). Failure to complete the vehicle properly is a penalty of up to hundreds of points relative to your competition, and well trained drivers could be worth up towards 100 points.

100% agreed. This is were you must find the right compromise. Of course you have to try to improve your design from year to year (at least that is the intent of the whole competition).
But to do well at comp you mustn't forget to build a car. We always have three goals for a season: Finish the car in time, finish endurance, win the competition.
This sounds simple. But you have to be aware that you can't achieve the third goal without having achieved the other two first.
You have to make your schedule for the year. You must define a design freeze. And after this day design changes must be rare exceptions (it's nearly impossible to have absolutely no changes anymore). From then on, you build the car. If one have of the team starts building the car and the other half goes on and on changing their designs you will get into serious trouble.
Like this everyone can take care that his parts get done and be sure they will fit into the car. It isn't acceptable that one manufactures a part and then it doesn't fit anymore because someone else changed his design.
Almost every year some team members aren't willing to really accept that, usually newbies ;-). They always argue that if they get some more tim to work on their design, they will be able to reach "the optimum". So you have to tell them that "the optimum" is something that doesn't exist. These last details you argue about at this time will help you to collect some points at best (as Geoff explained). But because of the loss of time the risk of losing reeeaaaally a lot of points is rising.

So the bottomline is that you need a schedule and that you have to stick to it (that must sound so German...). Only this makes it possible to get your car done early enough before comp. And the points you can gain during these weeks by setup work, driver training etc. will bring you way more points than using this time for optimizing some design details.

And by the way. Here in Stuttgart drivers are always chosen before the new car is done. Driving time with the new car is incredible valuable and you shouldn't waste it for some stupid sort of competition within the team. Of course everybody wants to drive, but if your goal is max. success you must be able to accept that only few people can drive the car before comp. Of course after the last competition for a car we make some team events and then everybody is allowed to drive.

[bob.paasch]

Originally posted by Bemo:
And by the way. Here in Stuttgart drivers are always chosen before the new car is done. Driving time with the new car is incredible valuable and you shouldn't waste it for some stupid sort of competition within the team. Of course everybody wants to drive, but if your goal is max. success you must be able to accept that only few people can drive the car before comp. Of course after the last competition for a car we make some team events and then everybody is allowed to drive.

We do exactly the same thing, at least in the beginning of the season.

[flavorPacket]

Originally posted by Mbirt:

She's also Chrysler's plan to get those pentastar Challengers down on mass, right?

She actually works for Chrysler now, so maybe that's true...

[Freddie]

Thanks Geoff! I'm the president of a new FS team and I will compile all your posts (like I've done with the thread start) and force everyone to read it.

I'm just wondering about your thoughts on concurrent engineering in FSAE design work? It's sort of bordering integrating design, I guess, but it would be great to hear what you think about it

[Big Bird]

Thanks Freddie. I certainly hope you are not going to compile all of my posts - your poor team members will be reading until August.

Interesting question on the concurrent engineering thing. I know that is a bit of a catchphrase at the moment, so I hope there isn't some hidden meaning that I miss. I don't have any formal training in concurrent engineering process, and simply understand it as an iterative, concurrent (obviously) design process.

My random thoughts, no particular order:
* FSAE is a classic concurrent engineering task - huge task to complete, not enough time to do it sequentially
* My page 1 design process (Levels 1-4, or what I'm now thinking of as "Project - Problem - Product - Parts") seems to indicate that we should follow each step sequentially. It will help organize your design process - but won't completely linearize it. There will always be some iterative stuff going on
* No design management structure will work if you don't have buy-in from your team members

I would say that if your overall design ethos is "hey, lets concurrently engineer!" you are in for a confused and painful project - and probably a non-delivery of the final car. I strongly advocate a solid, rational enquiry into your project (Level 4) followed by your problem (Level 3), to set the base direction of the team and to get everyone onto the same page. Once everyone (the majority?) agrees on a direction, let the concurrent engineering begin. Iterative design works well to solve packaging issues and solving inherent design compromises, but if you let it drive your whole project you'll not get anything done.

Note: going back to that buy-in thing - I believe concurrent design can only work when you have good communication between team members. And that means everyone gets together once a week (or more often?) to touch base and re-align. In our year we had a CAD review every Wednesday night from 6-9pm, pizzas and drinks brought in, and the whole team worked through packaging and design issues. It worked really well, and made sure everyone understood the overall design direction. If you have team members who think they already know it all and just want to be left to do their own thing - then you are probably better off doing the linear design thing.

In summary it all depends on your team. If you are all friends, then give the concurrent thing a go. If you have a fractious team, then linear is the only way you can control it.

Time to go to work....

Cheers

[Mbirt]

Originally posted by flavorPacket:
She actually works for Chrysler now, so maybe that's true...

Haha. Yeah. We've got two KUFSAE alums in the calibration group working with her to get more "Imported from Detroit" vehicles on the road.

[Bemo]

Originally posted by Big Bird:
And that means everyone gets together once a week (or more often?) to touch base and re-align. In our year we had a CAD review every Wednesday night from 6-9pm, pizzas and drinks brought in, and the whole team worked through packaging and design issues.

If you have the possibility design as much time as possible together in one room. Here at Stuttgart we have the great opportunity to use a CAD-Pool with enough computers to allow everyone design at the same time.
Like this smaller packaging issues etc. can be solved the short way without bothering your chief engineer.
The regular meetings at which the whole team discusses all aspects together to make sure nothing gets missed and to give everybody an understanding of what is going on are of course absolutely necessary.
Communication makes your team efficient. Lack of communication leads to sensless work and that leads to frustrated team members. It doesn't help anyone if everybody is designing into a different direction and in the end you try to match the pieces.
Sometimes you get a feeling that all the meetings just cost you valuable designing time but later you will recognize that they help to make your desinging time much more efficient.

[Freddie]

My mistake, I was referring to your posts in this thread. While reading all your posts on this forum may be useful, I have a slight guess that my team members will go berzerk somewhere around june ...

I'm no expert in concurrent engineering, or the "easy to explain, hard to perform" waterfall model either, so I was referring to the iterative parts of the process. The weekly meetings are already a routine to get everybody in the knowing about what's going on, and judging from your advice we will continue doing that.

Thanks again for your thoughts on this.

Bemo: great advice, I will try to incorporate it as soon as we get on to design of our car. Thanks!