Ever heard of the KISS (keep it simple, stupid) principle? The general idea behind it is that systems perform best when the design is simple, not complex. My favorite example demonstrating the application of KISS, as well as the impact of failing to do so, is captured in a scene in the 1995 movie Apollo 13. An incident necessitates three astronauts use the lunar module (LM), a ship built just for landing on the moon, as a lifeboat to survive. The LM is designed and equipped to provide two people 36 hours of life support, not three crew members the 96 hours it will take to get back to earth. As a result, the ship begins to develop an unsafe buildup of CO2. The LM CO2 filtration system uses cylindrical filters, all of which have been used up. The command module’s CO2 filters are square. This fact exemplifies a failure in executing the KISS principle between the designers of the LM (Northrop Grumman), the command and service modules (North American Aviation), and NASA. When NASA ground control realizes this, engineers are pressed to concoct a solution, demonstrating the successful application of KISS. In the movie, the engineers enter the room and dump a box of supplies (available to the astronauts) on a table. The lead engineer defines the problem verbally, visually, and simplistically. “We gotta find a way to make this [holds up the square filter in his right hand], fit into the hole for this [holds up the cylindrical filter in his left hand], using nothing but that,” he concludes, placing both filters back on the table and pointing to the available materials. When you see it, the problem seems obvious, the solution simple, and something which could have been prevented with better front end planning — KISS.