In the scenario of severe competition, most of the manufacturers would agree that Lead Time (LT) can be an effective competitive weapon as customers become less patient and less willing to wait for delivery of what they order. By reducing Lead Time, manufacturing companies not only can increase their efficiency and effectiveness, but also they will be responsive, committed and pioneering by bringing the new products to market quicker than their competitors. By implementing Lean/JIT (LJIT) practices within firm and between firms, we can reduce the lead time of the product. In this paper, we propose a research model for prioritizing lead time reduction with Within-firm supply chain integration (WFSCI) and Between Firms Supply Chain Integration (BFSCI). In this research, we try to reduce the lead time through implementation of Lean/JIT practices with supply chain integration.