Manufacturing has always been a competitive business. Over the past 20 years, international treaties designed to lower tariffs and foster competition has significantly increased the level of this competition. To survive in this environment a manufacturing business needs every tool it can find at its disposal. But the primary tools that exist in the business press – ERP, Lean Manufacturing (including related concepts like Theory of Constraints) and Six Sigma – are typically presented as stand-alone solutions. Each has its place, but the requirement of a modern manufacturing enterprise is to understand the strengths of each and when it’s appropriate to apply the tool. We will explore the relationships between each, discuss the tools themselves and the delicate balance that is required when implementing both lean manufacturing concepts and an ERP system. In conclusion, we will present examples from two recent clients, explaining how they dealt with this challenge.