Why systems development is different than building a bolt

but more is like a chemical process'.
In the book "Software development with Scrum" by Ken Schwaber and Mike Beedle they say
"I wanted to understand the reason that my customers' methodologies didn't work for my company, so I brought several systems development methodologies to process theroy experts at the DuPont Experimental Station in 1995. These experts, led by Babatunde "Tunde" Ogannaike, were the most highly respected theorists in industrial process control. They knew process control inside and out. Some of them even taught the subject at universities. They had all been brought in by DuPont to automate the entire product flow, from forecasts and orders to product delivery.
They inspected the systems development processes that I brought them. I have rarely provided a group with so much laughter. They were amazed and appalled that my industry, systems development, was trying to its work using a completely inappropriate process control model. They said systems development had so much complexity and unpredictability that it had to be managed by a process control model they referred to as "empirical". They said that this was nothing new, and that all complex processes that weren't completely understood requiered the empirical model. They helped me go through a book that is the Bible of industrial process control theory. Process Dynamics, Modeling and Control to understand why I was off track."