Requirements Are A Property Of The Design

Every other functional test would fail. The sensor interface error was out of bounds; nominal as it turns out. The technician writes a discrepancy ticket and moves on to another work order. This unit will pause testing for several days and sometimes several weeks. The responsible engineer would disposition the discrepancy use-as-is without even plotting the time-series data. The design engineer had attributed the out-of-bounds performance to noise, failing to realize this was a circuit that didn’t always meet requirements. Every responsible engineer since had inherited that disposition. This continued for three years. The unit was qualified to SMC-S-016. The test bounds were the requirements and there was no budget to redesign the unit. Three responsible engineers had shepherded this unit serially from design to volume production. Then I joined. “What’s the worst-case performance under temperature and manufacturing tolerance of the channel?” One engineering leader dismissed the…