the employee was an executive of the management and the management appointed two Junior Engineers and their works were being supervised by the said employee. 15. The law is well settled that the determinative factor for “workman” covered under section 2(s) of the I.D. Act, is the principal duties and functions performed by an employee in the establishment and not merely the designation of his post. Further, the onus of proving the nature of employment rests on the person claiming to be a “workman” within the definition of section 2(s) of the I.D. Act. 16. In the present case, there is no specific document adduced relating to the actual work and functions performed by the employee. In the absence of any concrete material to demonstrate the nature of duties discharged by the employee, the employment orders issued by the management will have to be taken into consideration and as per the same, the employee was appointed as Junior Engineer and was promoted as Assistant Engineer, on the