Internal lean manufacturing practices and operational performance: A meta-analysis approach

Among the major aims of any firm is to keep costs as low as possible. This has become even more critical during the COVID-19 era, where many businesses have been forced to operate below their stated capacity while others have closed shop. However, even before the pandemic struck, firms both domestic and multinational were already reeling from the cut-throat competition exacerbated by globalization, disruptive technologies, and heightened demand for cheap products and services with increasingly innovative features. To win and sustain such demand, fend off the competition and achieve efficiency with increased value, firms were already trying to streamline their operations using different production techniques, including the lean manufacturing strategy, albeit with mixed results Therefore, the debate on the efficacy of the ILMPs on OP continues to be a subject of substantial scholarly and practical interest. A substantial amount of theoretical and empirical literature on the relationship has been and continues to be investigated as a result of this. This accumulation of empirical evidence on the ILMP-OP association has gained traction that makes it necessary to carry out another synthesis of findings through a meta-analytic study. However, despite the great strides made in bridging the numerous disagreements in the ILMP-OP relationship, the literature still has significant gaps and discrepancies. For example, empirical evidence on the association is frequently varied, and theoretical debates have remained unexplained in general. This study aims to narrow the inconsistencies and gaps observed and obtain a clearer picture of the relationship between ILMP and OP. The ILMPs were derived from a proposed model by Shah and Ward (2003). They include statistical process control, total preventive maintenance, continuous flow production, employee involvement, setup time reduction, and pull production. OP as the dependent variable for the study was measured in terms of speedy delivery of materials, flexibility, high productivity, reduction in defects, high first-pass yield, reduced lead time, lower manufacturing costs, high product quality, and waste minimization. The study comprises 7,075 firms spread across the world and thirty studies published between 2010 and 2020. The meta-analysis results show a strong positive and significant association between aggregate ILMP and OP, and the same for all the individual practices and OP.