Karine, you twice mentioned friends in "their" companies. Their children. Their cars. Their money. Their companies? Native language speakers routinely write "their employers" or "my employer" unless they have equity in the company. You can use the inclusive genitive 'their' in groups that are non-financial in nature: country, family, village. I'm sorry I misunderstood your writing.

I suspect that by "suggestion Theoretical contribution and Managerial contribution" you are expressing your belief that by writing your study you must attempt to improve and benefit the industry and their employees that are the topic of your academic research. This perspective is a charming mixture of altruism, innocence and Chinese educational 宣� 思想 - proper ideology. Good luck with that.

I'm currently doing some academic research on Walt Whitman. I merely hope that it will increase my own understanding of his work. Poisoned by a Western education, I find learning to be its own reward, in need of no further prescriptive justification.