Mohd Salleh or Pak Leh was a faculty member of National Institute of Public Administration, Malaysia (INTAN) from 1974 -1984. His first  job was as a training administrator at the Training Directorate, Public Service Department, Malaysia after finishing his first degree in economics in 1970.

After leaving INTAN, he spent three years as the CEO of a company involved in quarrying and asphalt production before becoming a corporate trainer in 1987 when he was certified as the GRID instructor.

Armed with the above experiences and collaborating with two other experienced trainers in 1993, Salleh developed HOTS, (holistic organization transformation systems) a instrument-based, programed-learning organization development which was tested and applied in financial, service, oil and gas, property development, health care and manufacturing industry and also in the public sector organizations in Malaysia. Its application also found acceptance at the cross-cultural level, when Salleh took it to Singapore, Indonesia, Thailand, Sudan and South Africa.  What is distinct about this program is the take-home plan for implementation that can be followed through at work.  This creates sustainability to the program.

Salleh is able to do this by integrating his experiences with his academic exposures secured through his post graduate study at Institute of Social Studies , Erasmus University Holland where he obtained Dip D.A and MPA(1974) . Later he obtained his Ph.D in public policy from SUNY, Albany, New York (1981). He was also conferred Diploma In International Management by IFL, Sweden (1981) and World Bank Fellow, EDI Washington(1975).