Training Within Industry (TWI) is a structured training methodology that enables organisations to develop employee skills quickly, effectively, and consistently. Created during the Second World War to train new workers efficiently, TWI remains highly relevant today for onboarding, upskilling, and maintaining standardised work across diverse industries. Its emphasis on practical, standardised learning has made it a cornerstone of Lean and continuous improvement practices worldwide.
TWI was developed in the United States during World War II to overcome severe labour shortages as inexperienced workers replaced skilled tradespeople. The U.S. government launched the TWI Service to help supervisors and trainers teach essential skills rapidly while maintaining productivity and quality. The programme’s structured approach proved so effective that it was later adopted internationally, particularly in Japan, where it heavily influenced the development of the Toyota Production System (TPS) and modern Lean Manufacturing.
TWI is built on three core programmes: Job Instruction (JI), Job Methods (JM), and Job Relations (JR), each designed to strengthen workplace capability and consistency. The standard training method follows four key steps:
TWI is used across manufacturing, healthcare, logistics, and service sectors.
It is particularly valuable for onboarding new employees, training temporary or rotating staff, and supporting Lean transformation initiatives.
TWI accelerates learning curves, enhances quality, and reduces rework through a structured, repeatable approach to training. It empowers supervisors to teach effectively and workers to perform consistently, fostering a culture of continuous improvement. As a precursor to Lean and Six Sigma methods, TWI remains a proven system for building workforce capability and operational excellence.