For example, most development processes have excessively large batch size, overspecialized sub-processes, massive inventory, and slow learning cycles. Since the factory is a key area in which we have transformed our thinking, I consider it an excellent role model for what we have the potential to do in product development. Nonetheless, there are some subtleties in transferring these World Class Manufacturing techniques into the product development arena. Product development is truly different than manufacturing in certain critical ways. For example, manufacturing is a repetitive process with relatively low variability.
Product development is a non-repetitive process with high variability.
This means we cannot bring rational management to product development by using the deterministic math that works so well in manufacturing. Instead, we must use the math of stochastic processes, such as queuing theory and information theory. What is important about this is that when you use the right math you reach strikingly different conclusions about how to manage the process. For example, deterministic math says your development process can be loaded to 100 percent utilization before you will experience delays. In contrast, queueing theory says you will experience massive delays in your projects if you try to load your organization close to 100 percent utilization.