Jim Kellett Takes the Lead at ECAO 2011 ECAO Industry Conference

MEASURING PRODUCTIVITYImpact of Overtimeon Electrical LaborProductivity:A Measured Mile Approach By Dr. Awad HannaElectrical contractors are frequently facedwith the need to compress or accelerate theconstruction schedule as a result of addedscope, delays and/or a late start of activities.The most common approach to scheduleacceleration is the use of overtime and/or extended overtime. Extended overtimeoccurs when workers are required to workmore than 40 hours per week for longer thantwo consecutive weeks. Extended overtimecan be implemented using a variety of crewscheduling techniques, including five workdaysat 10 hours per day per worker – alsoknown as 5–10s – or by using 5-12s, 6-10s,6-12s, 7-10s, or 7-12s. However, researchhas shown that extended overtime resultsin increased fatigue, decreased productivity,a greater risk for injuries or accidents, andincreased absenteeism and turnover. Asa result, extended overtime significantlyincreases the cost of construction projects.Past research studies concluded that placingworkers on scheduled overtime reduceslabour productivity. Although several researchefforts have studied the effect of overtime onlabour efficiency, these studies have unknowndata sources and were conducted manyyears previously.A recent study commissioned and publishedby Electri International and authored by ProfessorHanna, President of Hanna ConsultingInc., and Professor of Construction at theUniversity of Wisconsin-Madison focused onthe analysis of scheduled and unscheduled(sporadic) overtime on labour productivityusing the Measured Mile Method. TheMeasured Mile Method (MMM) is the goldstandard of productivity loss measurements.This approach compares the unit productivitylevels during unimpeded time (during thereference schedule) to those during impactedtime (when using overtime) in order todetermine how significantly the project’sproductivity was impacted. The theory isthat the difference between a contractor’sProductivity110%100%90%80%70%Cummulative Productivity of 5x10 Scheduley = 0.0042x 2 - 0.0808x + 1.0945R 2 = 0.9687actual inefficient productivity and an identifiednormal productivity is the amount ofexcess cost to the contractor as a direct resultof labour inefficiencies and loss of productivity.As it is a reliable and widely acceptedmethod, this new study utilizes MMM toform the basis of a model to predict andforward price overtime labour inefficiencies.The MMM was successfully used in theNatkin & Co. v. George A. Fuller Co. (347y = 0.0035x + 0.6818R 2 = 0.636160%0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21WeekFigure 1- 5-10 model and Comparison to 1969 NECA ModelNECA HighNECA AvgNECA LowOntario Electrical Contractor38