The 5 Focusing Steps is a continuous improvement method originating from the Theory of Constraints and applied to production systems.

Projects have two dimensions of constraints: 

There is the constraint of the project, its Critical Chain.

There is the constraint of the portfolio, a person or department preventing from doing more projects. It is the portfolio bottleneck.

The goal is to identify this bottleneck and to find solutions to improve the work environment to get a better productivity from it.

It is not unusual to have this bottleneck in the wrong place...