The importance of correct measurement in Process Safety

In February 2008, a stealth bomber of the US airforce crashed soon after take off. The pilots ejected safely but the loss was USD 1.4 billion. Wikepedia mentions the following about the cause for the crash...
"The findings of the investigation stated that the B-2 crashed after "heavy, lashing rains" caused water to enter skin-flush air-data sensors, which feed data to the computerized flight-control system. The water distorted preflight readings in three of the plane's 24 sensors, causing the flight-control system to send an erroneous correction to the B-2 on takeoff. The B-2 quickly stalled, became unrecoverable, and crashed. The sensors in question measure numerous environmental factors, including air pressure and density, for data to calculate airspeed, altitude and attitude. Because of the faulty readings, the flight computers determined inaccurate airspeed readings and incorrectly indicated a downward angle for the aircraft, which contributed to an early rotation and an un-commanded 30-degree pitch up and left yaw, resulting in the stall"
Whatever advanced process control systems you may have, it ultimately depends on the measurement reading that the system receives. Focus on the integrity of your primary measuring devices.
Read the article about the crash in this link.