Who can do what
Skill mix as the constraint it really is, the single qualified person, and training as a way of relaxing it.
Skill Mix Is the Real Constraint
Why headcount is the wrong number for most rotas, how to express a shift requirement as a composition, and what changes when you do.
The Single Qualified Person
What a capability held by one person actually costs a rota, the three failure modes it produces, and why the arithmetic for removing it is almost always favourable.
Competence Records Nobody Updates
Why the record of who can do what drifts within months, the three kinds of drift, and a maintenance routine that takes ten minutes a month.
Training as a Way of Moving a Constraint
How to pick the training that actually changes a rota, why most training budgets do not, and the arithmetic that makes the case in one line.
Supervision Requirements
Why a supervision requirement constrains a rota twice over, and the difference between a person being present and being available.
The Person Everyone Routes Around
Every team has someone the rota quietly works around, why that arrangement is a constraint nobody has recorded, and the three honest ways to resolve it.
Cross-Cover That Exists Only on Paper
Why documented cross-cover arrangements fail at the moment they are needed, how to tell a real one from a nominal one, and the single test that distinguishes them.