Space Companies at Y Combinator(spacedotbiz.substack.com)

    Make the requirements less dumb. The requirements are definitely dumb; it does not matter who gave them to you. He notes that it’s particularly dangerous if an intelligent person gives you the requirements, as you may not question the requirements enough. “Everyone’s wrong. No matter who you are, everyone is wrong some of the time.” He further notes that “all designs are wrong, it’s just a matter of how wrong.”
    Try very hard to delete the part or process. If parts are not being added back into the design at least 10% of the time, not enough parts are being deleted. Musk noted that the bias tends to be very strongly toward “let’s add this part or process step in case we need it.” Additionally, each required part and process must come from a name, not a department, as a department cannot be asked why a requirement exists, but a person can.
    Simplify and optimize the design. This is step three as the most common error of a smart engineer is to optimize something that should not exist.
    Accelerate cycle time. Musk states “you’re moving too slowly, go faster! But don’t go faster until you’ve worked on the other three things first.”
    Automate. An important part of this is to remove in-process testing after the problems have been diagnosed; if a product is reaching the end of a production line with a high acceptance rate, there is no need for in-process testing.