Enhancing productivity in manual electronics assembly and inspection through illumination design

Purpose - The purpose of this paper is to identify, study and quantify the effects of lighting on yield and productivity in manual electronics assembly (MEA) and inspection as a limiting work design criterion. The study also examines the potential interactions among lighting option, workers' age, and years of experience. Design/methodology/approach - A three-factor full factorial experiment is adopted to statistically evaluate the independent variables (process yield and assembly time) versus randomly selected levels of three factors: type of light (low pressure sodium, mercury vapor lamps, and metal halide lamps measured in foot-candle luminaries), operator age, and years on the job. A residual analysis is also conducted to complement and corroborate the ANOVA findings. Findings - The study finds that metal halide lamps, based on the ANSI recommended ranges of 186-464 foot-candles, lead to significant increases in labor productivity and through-put, irrespective of operators' age and years of experience. Although these lamps have a significantly shorter life span than that of low-pressure sodium and mercury vapor lamps, the realized benefits far exceed the incremental cost of illumination devices. The results indicate that a modest capital investment is able to generate solid improvements in yield and processing time in a typical MEA environment. Originality/value - The relations between productivity and lighting intensity and type have never been studied in the area of MEA. This empirical study uncovers the effects through a systematic experimentation of this essential relationship in a typical MEA environment. The findings, which can be generalized to other facilities, are validated by an array of statistical procedures and proved to be significant. The paper contributes useful knowledge to the fields of engineering management and facility design.