Consider the example above. Asking “Why?” five times revealed entirely different challenges than might have been initially perceived.
The extra work steps and inventories seen on the shop floor were a result of a deeper issue. Rather than remove them directly (which might have increased disruption), the real answer is to address a supplier base issue, perhaps by creating multi discipline procurement teams better equipped to structure purchases in a way that can help suppliers deal with the sources of lag that undermine their performance (like Cessna did, as described in Chapter 3)