Correlations in between EAWS and OCRA Index concerning the repetitive loads of the upper limbs in automobile manufacturing industries

Upper limbs repetitive tasks are one of the main sources of risk for the workers of the manufacturing industries and the standards ISO 11228-3 and EN 1005-5 addressed this issue since 2007. EAWS (European Assembly Worksheet) is a 1st level ergonomic risk assessment method and it provides in its 4th section a score to measure the load level for the upper limbs based on a traffic light scheme. According to the relevant ISO/CEN standards, the OCRA Index is the preferred system to refer to in the evaluation of the biomechanical stress of hand-harm-shoulder system. This correlation study is based on a 45 workstations sample coming from the automobile manufacturing industry. According to the results, EAWS4 shows an excellent correlation with OCRA index (Spearman's rho correlation index 0.95). Being EAWS based on biometric statistical data distribution, its typical application is the process design phase, but adopting a conservative approach in the interpretation of EAWS4 score for risk mapping purposes, it provides an equivalent "reaction" pattern (countermeasures to be taken in the production phase) with respect of OCRA Index with an Odds Ratio ranging from 0.89 (OR-matched) to 1.00 (OR-conservative).     

Implementation guidelines for mass customization: current characteristics and suggestions for improvement

Interest in mass customization (MC) is increasing in both industry and academia. Academic research on MC implementation guidelines (IGs) has, however, lagged behind other research streams in the MC literature. The present article reviews the existing literature on MC-IGs and inductively derives a classification scheme for prior research findings to identify potential areas for further research. While the issue of what enables MC has been intensively researched, investigation of several questions is still required, such as which enablers should be implemented and in what sequence, depending on the specific context in which MC is pursued. Other areas for future study of MC-IGs include applicability context specifications, as-is analysis tools, hindrance factors and required resources. This article complements previous MC literature reviews by providing an overview of MC-IGs available in the literature, identifying the building blocks of MC-IGs and proposing a definition of MC-IGs that can be used as a basis for future research in MC implementation.     

On the meaning of ‘Waste’: review and definition

Waste reduction is one of the main principles of lean, but it has been taken for granted that we have a common understanding of what waste means. We first present a critical, qualitative discussion that identifies four distinct waste concepts. We then conduct a systematic review of the literature that examines the different uses of these concepts. We find that only the classic concept of the seven wastes and the concept of waste as non-value-adding activity are widely applied. However, both concepts are, at times, not only incompatible but used in a way that leads to open contradiction. A new definition, centred on an efficient, timely transformation process seeks to consolidate the literature. We outline two distinct waste types: (i) obvious waste, to refer to any waste that can be reduced without creating another form of waste; and, (ii) buffer waste, to refer to any waste that cannot be reduced without creating another waste. The paper has important implications for practice. To reduce waste, managers must undertake three interlinked tasks: the elimination of obvious waste; the reduction of variability to transform buffers into obvious waste; and, the balancing of remaining buffers to best achieve performance targets. The paper supports managers in their endeavours to identify waste, which is an important precursor to waste reduction/elimination.     

A geometric time-series model with an alternative dependent Bernoulli counting series

In this article, we first introduce an alternative way for construction of the generalized binomial thinning operator with dependent counting series. Some properties of this thinning operator are derived and discussed. Then, by using this thinning operator, we introduce an integer-valued time-series model with geometric marginals. Some conditional and unconditional properties of this model are derived and discussed. Some estimation methods are considered and for some of them, asymptotic properties of the obtained estimates are derived. Performances of the estimates are discussed through some simulations. Finally, a real data example is considered and the goodness-of-fit of this model is compared with the models based on the binomial, negative binomial, and dependent binomial thinning operators.     

An extension on INAR models with discrete Laplace marginal distributions

The main theme considered in this article is an integer-valued thinning operator with both positive and negative values, its properties, and a new time series with skew discrete Laplace marginals. Some properties of this model are discussed, as well as estimators of unknown parameters, similarities and differences with some other existing models, applications in real-life situations, and identification and approximation of latent processes affecting the concerning process.     

THE IMPACTS OF THE USDA BROADBAND LOAN AND GRANT PROGRAMS: MOVING TOWARD ESTIMATING A RATE OF RETURN

In this article, we evaluate the rate of return to government efforts to promote broadband. Specifically, we estimate the impact of USDA's broadband loan and grant programs on the average payroll per worker using zip code level data from the Zip Code Business Patterns for the period from 1997 to 2007. Our results indicate that two of the smaller broadband programs (the Pilot loan program and the broadband grants program) likely had no effect on local payroll per workers. On the other hand, the largest program in terms of funding and coverage (the current broadband loan program) likely had a positive impact. Our estimate implies that a $1 per capita increase in a particular zip code's one-time receipt of the current program broadband loan results in a $0.92 increase in payroll per worker annually. Our calculated point estimates of the benefit: cost ratios for this broadband program range from 1.98 to 2.99, depending on assumptions about the time frame over which benefits accrue. However, the confidence intervals are wide enough to include the possibility that the costs outweigh the benefits.(JEL L86, J30, O18)