Most supervisors are promoted on the strength of their technical ability — and then expected to teach, improve, and lead without ever being taught how. The Five Needs Model for Good Supervisors, drawn from Training Within Industry (TWI), identifies exactly what every supervisor needs to succeed: two types of knowledge and three types of skill. This practitioner guide by Allan Ung, TWI Master Trainer, explains each need and maps them to the TWI programmes that develop them.