13 ms·

>"Fail fast" applies to more than just software. Yes, but let's not take the analogy too far. For people who work in safety-critical design (including software

by bumby 4y ago

>"Fail fast" applies to more than just software. Yes, but let's not take the analogy too far. For people who work in safety-critical design (including software), it takes a different mindset than what is often prevalent in silicon valley. When the stakes are high, you don't really want to "move fast and break things". You can actually see this in SpaceX. In development when stakes are relatively low (e.g., no payload or passengers), the risk threshold is high. But they start taking a more measured approach when that risk starts to ratchet up. The danger being, advocates of one approach don't always know when/how to transition to the other.

shinryuu 4y ago
I think it's a matter of failing in a safe environment. Clearly that's what space x is doing. They fail spectularly, but they do so within the confines of a safe environment. For the real launch they've already mapped out the failure modes and are able to prevent them when it really matters.
- bumby 4y ago
  I've worked in aerospace. The organizations (both public and private) would all claim to fail "within the confines of a safe environment". One small BS detector is when there's some unplanned/unmitigated test outcome that gets characterized as a "test anomaly" rather than being transparent about the details. >they've already mapped out the failure modes and are able to prevent them when it really matters This remains to be seen. The shuttle also had all their failure modes mapped out. As did CST-100. Yet massive failures still occurred.
  - cdash 4y ago
    It doesn't remain to be seen. SpaceX has done this already with the Falcon rocket.
    - bumby 4y ago
      That...doesn't follow because F9 and Starship are different systems. Mercury and Gemini both had good track records. Apollo and Shuttle, not so much. Put differently, how much would you be willing to bet that their FMEA has caught literally every failure mode possible?
      - jjk166 4y ago
        Well in the case of the Shuttle both accidents that killed people were due to previously identified failure modes. At the end of the day, risk will always be a number greater than 0%. At some point someone is going to have to make a judgement call that the risk is low enough to proceed, and sometimes that call is going to be wrong.
        bumby 4y ago
        The failure modes may have been known but the effects were not. A FMEA needs both to work. Regarding the foam, they had a difficult time even recreating it after the fact. It was apparently only on a lark that they decided to turn the gun up to 11 and, viola, now the foam had the physical properties capable of damaging the tile catastrophically. So, yes, they knew the mechanism of foam shedding but did not realize the effect properly. With the o-rings, they similarly just didn’t have the test data for this conditions. They incorrectly extrapolated on the test data they did have.
version_five 4y ago
I agree with everything in your comment. One thing I've wondered about re space exploration though is how we reconcile what I think is pretty much universal acknowledgement that we have to do everything possible to avoid loss of life with the inherent danger of space travel, and the "drag" that a zero-tolerance safety focus can have on culture. Put another way, what would global exploration have looked like if sailors refused to accept the risks of early ocean crossings?
- bumby 4y ago
  That is a real issue. I think part of it involves creating a culture where it's acceptable to make failures as long as those failures were the result of a sound decision process. What you don't want is a culture that is either a) afraid to take any risk because they are afraid of career consequences or b) willing to roll the dice with bad decision processes due to biases and bad incentives. Example for a): bureaucrats who are unwilling to push the envelope because a bad outcome would effectively end their career Example for b): making high-risk decisions due cost/schedule pressure, like competition for a contract
- DoughnutHole 4y ago
  Early modern sailors were uneducated manual labourers with few economic prospects in a world where simply living as a lower class individual was more dangerous than nearly any job that exists in the developed world today. Sailing often paid better than jobs on land which made up for the risk, and it offered the potential of massive reward to the high class leadership of the vessel. There is no consummate economic incentive for being an astronaut. The incentive is the experience and making some impact on science, and while that motivates many people the probability of attracting the best and the brightest goes down as the probability of exploding goes up. I'd say there's unlikely to be enough of an economic incentive to justify riskier manned space travel until the earth becomes a whole lot less habitable.
  - lutorm 4y ago
    If what you're saying is true, how come astronaut programs have many more applicants than they can take? People have other goals in life beyond economic incentives. People volunteer for the military, and I don't think anyone's under any illusion this is risk free. The important thing is not lying to people about the risk involved.
mgfist 4y ago
> You can actually see this in SpaceX. In development when stakes are relatively low (e.g., no payload or passengers), the risk threshold is high. But they start taking a more measured approach when that risk starts to ratchet up. The danger being, advocates of one approach don't always know when/how to transition to the other. This corroborates "fail fast". They achieve reliability and safety by launching far more than traditional space companies and seeing failure in those launches. They prove it out before adding the risk of human lives or expensive cargo. Meanwhile traditional companies will develop their rocket for 15 years till it's "perfect". SpaceX figured out that achieving perfection is best done through actual attempts, not laboratory experiments.
- bumby 4y ago
  >This corroborates "fail fast". But it also shows "fail slow" later. My point is that "fail fast" is not some hard rule to abide by, but contextually dependent on the risk at stake.
  - lutorm 4y ago
    I mean, the whole point if failing fast is to stop failing faster. If you just keep failing fast without end you're not going to be around long...
    - deleted 4y ago
      [deleted]
    - bumby 4y ago
      See the last comment of my OP. The risk I'm poking at is a cultural one, where "failing fast" becomes an acceptable mode of operating, regardless of the context.
  - mgfist 4y ago
    Nothing contradicts that. SpaceX does do this contextually. Once they nailed down the Falcon 9 rocket, the boosters and the Merlin engine, they mostly stopped messing with it and focused on operational excellence. But to get to that point they failed fast, because it's the most effective way to get reliability.
phkahler 4y ago
Let's look back at Star Hopper. SpaceX literally hired a company that builds water towers to build a prototype tank for Starship - and flew it! They were primarily trying to figure out how to build it, move it, etc. Obviously the risk tolerance was high. That's really the difference between them and say Boeing. SpaceX starts with higher risk tolerance just to figure out the lay of the land, but they start reducing that tolerance as development progresses. Boeing aims for perfection out of the gate (apparently).
- bumby 4y ago
  Alternative take: SpaceX is so new they don't know what they don't know. Take their example of a failed F9 strut, where the material supplied by a vendor didn't come close to meeting the necessary specs. A mature aersopace company would have processes in place to check the material for these specs before use. SpaceX has since levied these new process checks, but prior to that failure lots people may have pointed to them as being more efficient because of their 'streamlined' process.
  - s1artibartfast 4y ago
    If you don't know something, your options are to pack up your bags and go home or try to learn.
    - deleted 4y ago
      [deleted]
    - bumby 4y ago
      Or, you can take a risk-informed approach, and understand what risks are prevalent (e.g., the risk of a bad vendor) and put the appropriate checks in place to mitigate that risk. "Learning" doesn't always mean taking the highest risk option and just rolling the dice.
      - s1artibartfast 4y ago
        Oh I totally agree, but that is a form of learning. If you don't know what you don't know, you must find out.
bick_nyers 4y ago
I previously worked in medical image processing/transcoding and you are correct, but most people probably don't know precisely how or why. The knee jerk mindset that most people have in safety-critical design, is being ultra conservative. In the fields of medical and space (and likely others), you have an asymmetrical risk-reward profile. Think about it this way, if an engineer takes a risk on refactoring some software logic, and it speeds the system up 3%, what is their reward? A raise? A promotion? Fat chance. If that refactor instead breaks 3% of the time; engines blow up, people die, customers yell at them, they get fired, perhaps in some situations they even get sued. The engineers then converge to a local maxima by the means of: "If it ain't broke, don't fix it", and various other ultra conservative leanings. This mindset also will often get selected for in hiring, and rewarded. Now take the limit of this as time goes to infinity, you have bloated, legacy software that is full of spaghetti code and can't take new features easily (if at all). In the case of NASA's space shuttle program, it was extremely expensive, and the cost wasn't falling significantly over time either. One might view ultra conservatism as the problem, but the real issue is the asymmetrical risk-reward profile. Solving that takes a head-on approach with great leadership, deploying capital, state of the art testing/QA, great deployment pipelines, and more. Shield people from the risk, and intentionally reward people when they push the envelope. Imagine if you had a software testing process and product specification that was 99.9999% effective (and no, yours is not even close to that), you could then move at a silicon valley "fail fast" pace and advance the technology and architecture rapidly.

by bumby 4y ago

shinryuu 4y ago

I think it's a matter of failing in a safe environment. Clearly that's what space x is doing. They fail spectularly, but they do so within the confines of a safe environment. For the real launch they've already mapped out the failure modes and are able to prevent them when it really matters.

bumby 4y ago
I've worked in aerospace. The organizations (both public and private) would all claim to fail "within the confines of a safe environment". One small BS detector is when there's some unplanned/unmitigated test outcome that gets characterized as a "test anomaly" rather than being transparent about the details. >they've already mapped out the failure modes and are able to prevent them when it really matters This remains to be seen. The shuttle also had all their failure modes mapped out. As did CST-100. Yet massive failures still occurred.
- cdash 4y ago
  It doesn't remain to be seen. SpaceX has done this already with the Falcon rocket.
  - bumby 4y ago
    That...doesn't follow because F9 and Starship are different systems. Mercury and Gemini both had good track records. Apollo and Shuttle, not so much. Put differently, how much would you be willing to bet that their FMEA has caught literally every failure mode possible?
    - jjk166 4y ago
      Well in the case of the Shuttle both accidents that killed people were due to previously identified failure modes. At the end of the day, risk will always be a number greater than 0%. At some point someone is going to have to make a judgement call that the risk is low enough to proceed, and sometimes that call is going to be wrong.
      - bumby 4y ago
        The failure modes may have been known but the effects were not. A FMEA needs both to work. Regarding the foam, they had a difficult time even recreating it after the fact. It was apparently only on a lark that they decided to turn the gun up to 11 and, viola, now the foam had the physical properties capable of damaging the tile catastrophically. So, yes, they knew the mechanism of foam shedding but did not realize the effect properly. With the o-rings, they similarly just didn’t have the test data for this conditions. They incorrectly extrapolated on the test data they did have.

version_five 4y ago

I agree with everything in your comment. One thing I've wondered about re space exploration though is how we reconcile what I think is pretty much universal acknowledgement that we have to do everything possible to avoid loss of life with the inherent danger of space travel, and the "drag" that a zero-tolerance safety focus can have on culture. Put another way, what would global exploration have looked like if sailors refused to accept the risks of early ocean crossings?

bumby 4y ago
That is a real issue. I think part of it involves creating a culture where it's acceptable to make failures as long as those failures were the result of a sound decision process. What you don't want is a culture that is either a) afraid to take any risk because they are afraid of career consequences or b) willing to roll the dice with bad decision processes due to biases and bad incentives. Example for a): bureaucrats who are unwilling to push the envelope because a bad outcome would effectively end their career Example for b): making high-risk decisions due cost/schedule pressure, like competition for a contract
DoughnutHole 4y ago
Early modern sailors were uneducated manual labourers with few economic prospects in a world where simply living as a lower class individual was more dangerous than nearly any job that exists in the developed world today. Sailing often paid better than jobs on land which made up for the risk, and it offered the potential of massive reward to the high class leadership of the vessel. There is no consummate economic incentive for being an astronaut. The incentive is the experience and making some impact on science, and while that motivates many people the probability of attracting the best and the brightest goes down as the probability of exploding goes up. I'd say there's unlikely to be enough of an economic incentive to justify riskier manned space travel until the earth becomes a whole lot less habitable.
- lutorm 4y ago
  If what you're saying is true, how come astronaut programs have many more applicants than they can take? People have other goals in life beyond economic incentives. People volunteer for the military, and I don't think anyone's under any illusion this is risk free. The important thing is not lying to people about the risk involved.

mgfist 4y ago

> You can actually see this in SpaceX. In development when stakes are relatively low (e.g., no payload or passengers), the risk threshold is high. But they start taking a more measured approach when that risk starts to ratchet up. The danger being, advocates of one approach don't always know when/how to transition to the other. This corroborates "fail fast". They achieve reliability and safety by launching far more than traditional space companies and seeing failure in those launches. They prove it out before adding the risk of human lives or expensive cargo. Meanwhile traditional companies will develop their rocket for 15 years till it's "perfect". SpaceX figured out that achieving perfection is best done through actual attempts, not laboratory experiments.

bumby 4y ago
>This corroborates "fail fast". But it also shows "fail slow" later. My point is that "fail fast" is not some hard rule to abide by, but contextually dependent on the risk at stake.
- lutorm 4y ago
  I mean, the whole point if failing fast is to stop failing faster. If you just keep failing fast without end you're not going to be around long...
  - deleted 4y ago
    [deleted]
  - bumby 4y ago
    See the last comment of my OP. The risk I'm poking at is a cultural one, where "failing fast" becomes an acceptable mode of operating, regardless of the context.
- mgfist 4y ago
  Nothing contradicts that. SpaceX does do this contextually. Once they nailed down the Falcon 9 rocket, the boosters and the Merlin engine, they mostly stopped messing with it and focused on operational excellence. But to get to that point they failed fast, because it's the most effective way to get reliability.

phkahler 4y ago

Let's look back at Star Hopper. SpaceX literally hired a company that builds water towers to build a prototype tank for Starship - and flew it! They were primarily trying to figure out how to build it, move it, etc. Obviously the risk tolerance was high. That's really the difference between them and say Boeing. SpaceX starts with higher risk tolerance just to figure out the lay of the land, but they start reducing that tolerance as development progresses. Boeing aims for perfection out of the gate (apparently).

bumby 4y ago
Alternative take: SpaceX is so new they don't know what they don't know. Take their example of a failed F9 strut, where the material supplied by a vendor didn't come close to meeting the necessary specs. A mature aersopace company would have processes in place to check the material for these specs before use. SpaceX has since levied these new process checks, but prior to that failure lots people may have pointed to them as being more efficient because of their 'streamlined' process.
- s1artibartfast 4y ago
  If you don't know something, your options are to pack up your bags and go home or try to learn.
  - deleted 4y ago
    [deleted]
  - bumby 4y ago
    Or, you can take a risk-informed approach, and understand what risks are prevalent (e.g., the risk of a bad vendor) and put the appropriate checks in place to mitigate that risk. "Learning" doesn't always mean taking the highest risk option and just rolling the dice.
    - s1artibartfast 4y ago
      Oh I totally agree, but that is a form of learning. If you don't know what you don't know, you must find out.

bick_nyers 4y ago

I previously worked in medical image processing/transcoding and you are correct, but most people probably don't know precisely how or why. The knee jerk mindset that most people have in safety-critical design, is being ultra conservative. In the fields of medical and space (and likely others), you have an asymmetrical risk-reward profile. Think about it this way, if an engineer takes a risk on refactoring some software logic, and it speeds the system up 3%, what is their reward? A raise? A promotion? Fat chance. If that refactor instead breaks 3% of the time; engines blow up, people die, customers yell at them, they get fired, perhaps in some situations they even get sued. The engineers then converge to a local maxima by the means of: "If it ain't broke, don't fix it", and various other ultra conservative leanings. This mindset also will often get selected for in hiring, and rewarded. Now take the limit of this as time goes to infinity, you have bloated, legacy software that is full of spaghetti code and can't take new features easily (if at all). In the case of NASA's space shuttle program, it was extremely expensive, and the cost wasn't falling significantly over time either. One might view ultra conservatism as the problem, but the real issue is the asymmetrical risk-reward profile. Solving that takes a head-on approach with great leadership, deploying capital, state of the art testing/QA, great deployment pipelines, and more. Shield people from the risk, and intentionally reward people when they push the envelope. Imagine if you had a software testing process and product specification that was 99.9999% effective (and no, yours is not even close to that), you could then move at a silicon valley "fail fast" pace and advance the technology and architecture rapidly.