More than anything, the LEGO System’s greatest value resided in its benefit to manufacturing, for it shielded LEGO from much of the rapid shifts in kids’ tastes. … Thanks to the LEGO system, however ,the company’s forecasters understood that no matter what kits kids lusted for — LEGO City, Star Wars, or something entirely new — it could still produce bricks, minifigs, wheels, windows, and thousands of other components every day of every year, just as it had done for decades. The sets and themes would change, but many of the components remained the same. Because most components were compatible across so many different kits, LEGO could reap enormous cost savings by not having to dramatically change its manufacturing operations from year to year. Knudstorp knew this intuitively, but his conversations with Kristiansen brought into sharper focus the notion that the LEGO System is an all-encompassing business system.
– David C. Robertson with Bill Breen Brick by Brick