How do different organisations bring more ethical transparency and clarity in supply chain/procurement dealings?

First of all, i would like to say, ethics comes from within the person. But there is a proverb, to err is human. Thus, to rectify this situation, different rules and regulations comes to the point. Through those rules and regulations, the regulatory committee strongly monitors the supply chain or procurement activities. This is very natural that, without proper monitoring  there always remains some gaps in the process which questions the transperancy and ethical issues. 

Thus, by ensuring strict follow up and regular audit by internal regulatory bodies considering the rules and regulations as benchmark, different organizations can bring more efficiency, transparency among the activities with strong ethics.

You should have regulations that governs everything and there should be away to calculate risk assessment. 

Moreover there could be an Ethics and Compliane unit to monitor any abuse of the present procedures.