sqrt_minus_1

11 yıl öncediscuss

> It would be stupid to steal a Tesla for anything other than a joy ride and unless you're talking a hostage scenario I don't know what about a Tesla driver suggests they have a large amount of cash on them.

I agree. But driving around in a very expensive car is a great way to signal you have other very expensive things like fancy phones, laptops, watches, etc., that can be quickly disposed of for cash.

> It sounds like an awful suburban strip mall, but not a place where you should be worried about a car jacking.

Violent crimes of all sorts happen in suburban strip malls all the time. Guess it never happened for you. Didn't find any crime maps available for the area. I would expect Tesla to locate stations in good areas based solely on good business sense.

I get that Teslas are interesting cars and their owners like to defend them, but to pretend there are no personal security considerations for Supercharger stations strikes me as irrational.

sqrt_minus_1

11 yıl öncediscuss

I don't have feelings one way or the other about the answer, and don't appreciate being told how I should feel. In Atlanta, the only two Superchargers I'm aware of (also the only two on the map) are at the Tesla dealer and at a large work/live/play location (Atlantic Station). Neither is at all convenient if you're driving through the area. I get that things are probably great in California, but from what I can see from the article and around town things are different in the Midwest and on the east coast.

Edit: and what the hell are you trying to imply with "women traveling solo"?

sqrt_minus_1

11 yıl öncediscuss

I assure you, my question is sincere and I don't appreciate being dismissed like that.

From the article:

  the Tesla predicts 40 minutes of charging is required to 
  juice the battery to its 230-mile-ish “daily limit”—and no 
  meal coinciding with the stop, I’m left to pace around an 
  empty Hobby Lobby parking lot.

I can't say either way, but that doesn't sound near an interstate exit with places to eat (but I'll grant that enthusiast press often embellishes for effect, could have been right next to a Waffle House). Compared with a gas station, an empty parking lot seems to be a riskier place to be waiting around.

sqrt_minus_1

11 yıl öncediscuss

What's security like at Tesla Supercharger stations? Some of the pictures make it seem like they're a bit isolated and unpopulated. Needing to wait for half an hour or whatever with your car plugged in (non-operable) would seem to make one a possible crime target. Plus, it'd be a safe assumption that you have money, given what you're driving around in.

sqrt_minus_1

11 yıl öncediscuss

I did neglect people and am wrong in doing so; I think what you say is absolutely correct.

sqrt_minus_1

11 yıl öncediscuss

Money. Time helps.

Creating reliable software-intensive systems is something we know how to do, we have repeatedly done it in the past, and we are doing in the present. Only problems are it ain't cheap in terms of money or time, so to be cost effective, the costs associated with failure or malfunction must be high.

Safety critical systems (where human health can be endangered by system failures and malfunctions) are one such system. They're usually developed under some sort of regulatory oversight (e.g., FAA, FDA). There are a set of minimal government standards that must be met, much of these related to documentation, and much of the documentation relating to risk analysis and quality management. There are also standards administered by industry groups---often, these are "voluntary" in name but for liability reasons practically required (in my experience). There's going to be some sort of (mandated) monitoring of the product after release (which feeds into the quality system) to correct design flaws, defects, etc. You have regulatory affairs people on staff to handle this area. The safety critical system itself is developed under some sort of formal product lifecycle management system. There will be a formal set of requirements. Early in the process, there will be a risk analysis (continually updated) of the design. There will be an a priori development plan, timeline, and cost estimates. As for development models, the waterfall model is alive and well, in part because it coöperates with the demanding documentation requirements; waterfall does seem to be on the decline in favor of more agile models (but not too agile!).

The software itself may be assembler if you're really resource constrained, but more likely, it will be C or C++ with a restrictive coding standard, or real-time Java, or possibly Ada. If you're fancy (and progressive), there might be a system model with automatic code generation. The tooling you adopt (e.g., from Atego) will assist with verification and validation, as well as requirements traceability. Most people, I think, find software work under these conditions to be boring and frustrating---it's certainly limiting. You're maybe generating 100 SLOC a day? The system is almost certainly running on some sort of real-time OS like vxWorks or QNX, and the hardware, software, and any associated libraries are (as much as possible) validated for use for your application. You can, given the right circumstances, use COTS software (a.k.a. SOUP, software of unknown pedigree), but then the validation becomes your responsibility.

The HN crowd hates it, but in my experience on these sorts of projects, degrees and certifications are required and expected except at perhaps the very lowest level of employees. Electrical and mechanical designs are probably stamped by a real engineer; depending on the nature of the software portion (and where it's being developed) the software design might get stamped too, but more likely, it's being supervised by someone with a bunch of industry-relevant certifications.

I've glossed over a ton, and skipped even more.

In my opinion: I think that the most important lesson to learn from safety critical projects (and good engineering practice in general) is that tools are not the major driver of quality: proper engineering processes and quality management are the driver of quality. A "right-sized" product lifecycle management plan, including a "right-sized" quality system are critical and necessary to predictably and reliably produce a quality product. All else being equal, I'd predict that a C application developed under a lightweight PLM and QMS will be superior to one developed under Agile and Rust, or Scrum and Haskell, or whatever the du jour fad might be.

sqrt_minus_1

11 yıl öncediscuss

On "how should I choose?", have you considered a decision matrix?

sqrt_minus_1

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