Quantifying the Cumulative Impact of Change Orders for Electrical and Mechanical Contractors

Factors influencing the probability that changes led to labor inefficiency included Percent Change, Estimated and Actual Peak Manpower, Processing Time, Overmanning, and Overtime. These factors can be appied to an equation to determine the confidence that changes impacted labor inefficiency. (RS158-1, pp. 10-11)

RT-158 identified six variables that can be used to quantify labor inefficiency (RS158-1, pp. 15-16):

• Percent Change
• % PM Time on Project
• % of Changes Initiated by the Owner
• Productivity Tracking
• Overmanning
• Processing Time

 

• The most common reasons for change orders are Additions, Design Changes, and Design Errors. Therefore you should do more up-front engineering.
• Reduce change order processing time to decrease the likelihood of impact.
• Require contractors to submit a manpower loading curve with proposal.

 

• Integrate any changes into the work flow as efficiently as possible.
• Use project software to track productivity:
  • % complete by earned value
  • % complete by actual earned work-hours
  • % complete by actual installed quantities
• Resource loading relationships (ratios):
  • Actual peak over actual average manpower
  • Estimated peak over actual peak manpower
  • Actual manpower loading curve versus estimated manpower loading curve