Monitoring productivity with eva

Monitoring Productivity with Earned Value Analysis – A New Approach A.D. Mattos , R. Delarue 1 Acciona, Sao Paulo, SP, Brazil 2 Systech International, Dubai, UAE
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R. Pedroso Alvarenga, 85 – aptº 141 – Sao Paulo, SP, 04531-010, Brazil, +55-11-3167-5727, aldo@aldomattos.com 2 Office 314, Building 9, Dubai Media City, PO Box 502374, Dubai, UAE, +971 55 739 0123, ricardo.delarue@hotmail.com.Labour has an undeniable effect on a construction project and represents a major source of risk for the contractor. Better (or worse) than expected productivity certainly causes a positive (or negative) impact on the global schedule and cost, and thus must be properly monitored and controlled. Measuring the efficiency of direct manpower is a task ordinarily carried out by many contractors, butkeeping records of quantities of work performed and the corresponding man hours is not enough. Some questions remain: (i) what is the overall efficiency of the manpower?; (ii) what is its impact on the project as a whole?; (iii) what is the trend of the labour production rates, and how does it affect the originally estimated scenario? In this paper the authors introduce the concept of Labour CostPerformance Index and Labour Schedule Performance Index and present a methodology for measuring and interpreting productivity and forecasting trends by means of Earned Value Analysis.

Considering that manpower can represent more than half of a construction project total cost, labour has an undeniable effect on the project financial outcome and represents a major source of risk for the contractor.Better (or worse) than expected productivity certainly causes a positive (or negative) impact on the global schedule and cost, and thus must be properly monitored and controlled. Generally speaking, deviations in the estimated labour cost occur due to variations of productivity (or production rate). There are several reasons for the discrepancy between estimated and actual production rates: a) b)c) d) e) f) g) h) Productivities from similar jobs are used, but cannot be achieved in the field; Labour shortage and absenteeism; Availability of skilled labour; Acceleration (directed or constructive); Adverse or severe weather; Interferences; Cumulative impact of multiple changes and rework; Training and motivation; etc.

Measuring the efficiency of direct manpower is a task ordinarilycarried out by many contractors, but keeping records of quantities of work performed and the corresponding man hours is not enough. It is important to compare what has been done to what was originally planned and forecast the cumulative productivity at the completion of the job. In other words, the scheduler/planner must be able to assess the performance of the field crews and evaluate the trend in thefuture. Some questions remain: (i) what is the overall efficiency of the manpower?; (ii) what is its impact on the project as a whole?; (iii) what is the trend of the labour production rates, and how does it affect the originally estimated scenario?; (iv) what actions must be taken to bring the job to the desired standards? In this paper the authors propose a methodology for measuring andinterpreting productivity and forecasting future behaviour by means of Earned Value parameters not referred to in terms of dollars, but rather in hours — the concept of Planned Hours, Actual Hours and Earned Hours are the basis of the proposed technique.

Control Unit During the process of construction cost estimating, the work breakdown structure (WBS) of the project is used to detect the services tobe estimated. The unit cost of each one of them is calculated by means of a cost spread that depicts the cost categories included in it — labour, material, equipment. Due to the fact that the unit cost spread portrays the production rate of the manpower, it is a very important tool to the planner. It can be stated that productivity is the numerical tie-in of estimating and planning. The...