Estimating Optimal Labor Productivity: A Two-Pronged Strategy

Abstract

In an attempt to evaluate the efficiency of labor-intensive construction operations, project managers compare actual with historical productivity for equivalent operations. However, this approach towards examining productivity only provides a relative benchmark for efficiency and may lead to the characterization of operations as authentically efficient when in reality such operations may be only comparably efficient.Optimal labor productivitythe highest sustainable productivity achievable in the field under good management and typical field conditionscan provide an absolute benchmark for gauging performance. This optimal productivity level is lower than the productivity frontierthe theoretical maximum achieved under perfect conditionsbecause of system inefficiencies, which emerge due to factors outside the control/influence of project managers. Conversely, optimal labor productivity tends to be higher than actual labor productivitythe productivity achieved in the fieldbecause of operational inefficiencies, which are the result of suboptimal managerial strategies. Estimating the magnitude of these system and operational inefficiencies will help project managers determine optimal labor productivity.This paper develops a two-prong strategy for estimating optimal labor productivity. The first prong represents a top-down approach that estimates optimal productivity by introducing system inefficiencies into the productivity frontier. A Qualitative Factor Model is used to determine the impact of system inefficiencies. This top-down approach yields the upper level estimation of optimal labor productivity. The second prong is a bottom-up approach that determines optimal labor productivity by removing non-contributory work from actual productivity in a discrete event simulation. This bottom-up approach generates the lower level estimation of optimal labor productivity. An average of the upper and lower limits reveals the best estimate for optimal labor productivity.In conjunction with a relevant literature study and a discussion of the twoprong approach's methodology, this paper ultimately analyzes data from a pilot study, presents results, and evaluates the feasibility of this two-prong strategy for estimating optimal labor productivity in construction operations. 757 INTRODUCTIONProductivity is generally defined as the ratio of output to input. Yi and Chan (2013) concluded that hourly output is the most reliable measurement of productivity for construction activities. For labor-intensive operations, the focus of analysis is labor productivity, which measures the input as labor hours and the output as installed quantities (Dozzi and AbouRizk 1993). Traditionally, such labor productivity has been benchmarked against historical averages. However, this practice only provides a relative measure of efficiency since no objective yardstick exists. Optimal labor productivity, defined as the level of sustainable productivity that may be achieved in the field under good management and typical field conditions (Son and Rojas 2...

A Case Study on Estimating Optimal Labor Productivity

“…This model identifies the factors that influence productivity and assigns severity scores and probabilities of each factor's occurrence by experts. Detailed explanation of this model is found in Kisi et al (2014). The procedure of assigning severity scores and probabilities are followed as same as explained in Kisi et al (2014); however the factors are different because of different work environment.…”

“…Figure 1 depicts different productivity levels once the steady state condition is reached for a construction operation. The details are explained in Kisi et al (2014). The two-prong strategy for estimating optimal labor productivity assesses system and operational inefficiencies.…”

“…This assessment implies that there are no benchmarks or standards to validate historical data as appropriate for either estimating or evaluating productivity. Kisi et al (2014) developed a two-prong strategy, which contains both qualitative and quantitative models. Figure 1 depicts different productivity levels once the steady state condition is reached for a construction operation.…”

“…Since no substantive models for estimating optimal productivity have been proposed in the construction domain, a two-prong strategy was developed and successfully tested in a simple electrical installation task ). However, the study by Kisi et al (2014) was limited to a single task, with a single worker, performing only sequential actions. This study, therefore, enhances the body of knowledge in construction engineering and management by applying the two-prong strategy for estimating optimal labor productivity in labor-intensive construction operations with multiple workers for both sequential and parallel operations.…”

شبیه‌سازی بهره‌وری با استفاده از یک پارچه‌سازی رویکردهای شبیه‌سازی پویایی سیستم و مدل سازی عامل‌محور

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