The 100% utilization mentality comes from the factory assembly-line manufacturing process, where everyone is just a cog doing simple and repeatable thing. It's

The 100% utilization mentality comes from the factory assembly-line manufacturing process, where everyone is just a cog doing simple and repeatable thing. It's easy to get close to 100% utilization. However, it fails miserably in the creative process of software development. But unfortunately many managers at all levels adhere to it and use it in planning and project management. It's one of the reasons software project is often over budget and late in delivery. Of course the developers are miserable, too.