This leads them to load their processes to dangerously high levels of utilization. How high? Executives coming to my product development classes report operating at 98.5 percent utilization in the precourse surveys. What will this do? Chapter 3 will explain why large queues form when processes with variability are operated at high levels of capacity utilization. In reality, the misguided pursuit of efficiency creates enormous costs in the unmeasured, invisible portion of the product development process, its queues.
Donald G Reinertsen in The Principles of Product Development Flow