The simplest response to the question is, “Lean is how you run your business, Six Sigma is how you solve problems, and PMP helps ensure that all continuous improvement efforts are completed on time and on budget.” To better understand this answer, we must first look at the differences between the three methodologies.
Lean – The common misconception about Lean is that it is a “tool kit”. Lean is not a tool kit. Toyota did not achieve what it did by using tools. Lean is a system that ties the entire organization together. Tools and management philosophies typically focus on just one area or aspect of a business. In Lean speak, we would call this sub optimizing the value steam. Lean starts with the Leadership team understanding how a Lean organization thinks and behaves. It focuses on long-term value for the three customers: shareholders, employees, and external customers.
Six Sigma - A process for solving problem using the DMAIC (Define, Measure, Analyze, Improve, Control) data based decision making process. While the methodology is great for solving complicated problems, my experience has been that most business problems are not complicated, and poor performance is usually a lack of basic standards or the discipline to follow those standards. I often ask people, “If you throw Lean Six Sigma tools at a bad strategy, what do you get?” The answer – bad results faster. I have never seen a Six Sigma book discuss business strategy or human resources strategies. Both need to be in place before an effective Six Sigma program can be achieved.
PMP (Project Management Professional) – Practitioners are taught how to properly plan and execute projects. Concepts like critical path, communication, and budgeting are used. The PMP institute certifies people as a PMP.