The joint, mediating, and interactive effects of three elements of labor and machine flexibility on mix flexibility were tested empirically in a PCB assembly plant. Both subjective and objective data were collected. Some elements of labor and machine flexibility mediated the relationship between an emphasis on competitive priorities and mix flexibility. The interactive effects of machine and labor flexibility on mix flexibility confirmed prior findings that the pursuit of total flexibility is not desirable. For low levels of labor flexibility, increasing machine flexibility yields at the most a very moderate improvement in mix flexibility. When labor flexibility is high, increasing machine flexibility proves to be counter-productive. These results may suggest that the traditional forms of labor flexibility need to evolve when technological capabilities are more fully exploited.
Manufacturing flexibility is often construed as the ability to respond quickly to change with minimum penalty (Gerwin, 1993 and Koste and Malhotra, 1999). Despite being touted as an important strategic weapon, flexibility is not formally managed like quality and cost (Cox, 1989 and Zammuto and O’Connor, 1992). Two problems engender this phenomenon: measurement deficiencies and the ensuing lack of empirical research. Flexibility remains an abstract concept to most manufacturers, and its measures tend to be industry or even sample-specific (Dixon, 1992). Nevertheless, the past years have witnessed constructive measurement efforts with the development of taxonomies identifying the facets of this multi-dimensional construct (Buzacott, 1982, Slack, 1983, Slack, 1988, Gerwin, 1987, Sethi and Sethi, 1990, Gupta and Somers, 1992 and D'Souza and Williams, 2000). A dominant perspective in analyzing the relationships among these facets has been the hierarchical view (Browne et al., 1984, Slack, 1987, Sethi and Sethi, 1990, Hyun and Ahn, 1992, Suarez et al., 1996 and Koste and Malhotra, 1999). According to this view, resource flexibilities (labor and machine) are the lowest level dimensions and serve as the building blocks of the hierarchy. Although this hierarchical model is conceptually sound, there is only sparse evidence to support it. Moreover, the hierarchical model does not capture the antecedents of resource flexibility. There is a general consensus that resources are aligned to enable the achievement of excellence in the competitive priorities, i.e., cost, quality, time, and flexibility (Miles and Snow, 1984, Jackson et al., 1989, Cappelli and Singh, 1992 and Hayes et al., 2005). Unfortunately, scarce empirical evidence also afflicts this line of research. The purpose of this study is to fill these gaps by: (1) focusing on the sound operationalization of labor, machine, and mix flexibility; (2) examining the influence of competitive priorities on resource alignment; and (3) testing the premise of the hierarchical model that labor and machine flexibility contribute to a higher-level capability, i.e., mix flexibility. Further justification for this endeavor is provided below.
It is the first one to confirm empirically the importance of individual workers’ flexibility in boosting production variety, even in the presence of sophisticated equipment. It validates the hierarchical model of flexibility in reaffirming the role of labor flexibility as a building block of mix flexibility, but it suggests the existence of nuances. RN-flexible workers seem especially valuable in situations where machines are ill-equipped to handle a varied mix. This contribution wanes as machine flexibility increases. In this respect, this study extends Malhotra and Ritzman's (1990) findings. It also highlights the challenges of developing labor flexibility (RH) effectively. Based on our results, it seems that the development of such capability should be confined to less complex environments.
