Which of the following is a recognized source of material cost overruns when comparing estimated versus actual materials on an electrical job?

When comparing estimated versus actual material costs, a contractor may identify various reasons for a cost overrun. Match each real-world scenario with the correct cause of the material discrepancy.

You are reviewing the estimated versus actual materials for a residential wiring job that went $300 over its material budget. Your lead electrician explains that the homeowner verbally requested three extra dimmer switches and a ceiling fan during the installation. The crew installed these items using parts from the truck but never officially added them to the customer's final invoice. In your variance analysis, this specific overrun should be categorized as an unbilled ______ change.

While reviewing the estimated versus actual materials for a completed commercial wiring job, you discover a significant material cost overrun. However, the field reports and invoices show that the exact number and type of materials originally estimated were purchased and installed, with zero wasted or leftover units. Based on this comparison, it is accurate to conclude that the cost overrun was caused by missed takeoff quantities.

You have just completed a commercial lighting installation and discovered that actual material costs exceeded your estimate by 18%. To most efficiently diagnose the root cause of this overrun, arrange the following investigative steps in the order you judge to be most effective — starting with the step that establishes the most critical baseline and ending with the corrective action.