Derek J. Hatley

Derek J. Hatley was a British-born author and systems engineer, best known for co-developing the Hatley–Pirbhai modeling technique for real-time system specification. He served as president of System Strategies, an international consulting and training firm based in Jenison, Michigan, and previously worked as a Staff Engineer at Smiths Industries. Hatley authored influential books such as 'Strategies for Real-Time System Specification' and contributed significantly to systems engineering methodologies.