The difference is the two is the government has certain authority and rights that commercial enterprises do not have in my opinion. The government is not in the business in making a profit. There are certain price limits set by the government that can not be exceeded majority of the times when making purchases. In Federal Government contracting, specific regulatory authority is required for the Government's agent to enter into the contract, and that agent's bargaining authority is strictly controlled by statutes and regulations reflecting National policy choices and prudential limitations on the right of Federal employees to obligate Federal funds. Commercial purchases on the other hand , is mainly guided by profit motivations. Each commercial/private vendor represents itself and can obligate their purchases in its own manner.
2. What are the skill sets that a purchasing and supply management professional should possess or acquire to be successful in the exercise of the purchasing functions with commercial or Governmental organizations?
The skill set that a purchasing, and supply management professional, should possess or acquire successful is, relationship/team building skills. The ability to deal with a client /vendor or manufacture and come to terms and or agreement, that will benefit both parties. I also think you should have some prior experience 2-4 years in purchasing or supply management . Lastly, holding a degree in business management, contract services or acquisition management should also be a necessary skill.