Pragmatic Project Management and Systems Engineering Philosophy

Historically prudent engineers would design with 2x and 4x margin to ensure success. They were working with hand calculations and graph paper. Today we have computer aided design and routinely simulate many aspects. Why are we still designing with 200-400% margin when we have solid data?  

Too much margin drives up development costs and cause extra delays.  In the end as tolerance for cost overruns and delays grow people decide to accept many criteria are ok after all.  Why not start with a better understanding of what is important and design to that?

Prudent designs still need some margin.  Too little will lead to more rework in the factory and unacceptable field failure rates. While we don't want to over design we also do not want to turn customers into the most expensive version of quality control.  They are buying this because it adds more value than it costs, so when it fails the burden to customers is that much higher. Early adopters will accept the first versions are not perfect have enough margin to minimize this.

The goal are designs that customers consider barely adequate, on time and within budget and last as long as expected.