Discuss the variables that are crucial for evaluating the efficiency of a PM system. Focus discussion on four to six key variables. Include the following: *Describe why each variable is important to measure. *Discuss at which stages in the PM process the variables should be measured. *Determine the risks associated with not measuring the variables. Analyze how this information can be used to form best practices and to improve a PM system. Include at least two peer-reviewed references. The textbook will not count as a required peer-reviewed reference. Smither, J. W., & London, M. (Eds.) (2009). Performance management: Putting research into action. San Francisco, CA: Jossey-Bass.