Eliyahu M. Goldratt
Keeping every resource busy can build inventory without raising throughput. In The Goal, improving the whole system's output starts with addressing the bottleneck that limits it.
You must clearly define your organization's ultimate goal to ensure every action taken is genuinely productive.
A bottleneck dictates the maximum output of your entire operation, so lost time at this constraint means lost revenue for the whole system.
Trying to keep every employee constantly busy creates excess inventory and hides the true limitations of your workflow.