Though Lean and Six Sigma originated as two different strategies, in two different environments, with different tool sets and methodologies, they are increasingly being seen as similar approaches. In keeping with this perspective, the combined methodologies are referred to as Lean Six Sigma.
Each methodology has a different focus and brings different strengths to the union.
Lean
Lean focuses on increasing the velocity or efficiency by eliminating barriers and streamlining processes and reduces costs by decreasing waste and nonvalue-added activities.
Six Sigma
Six Sigma focuses on eliminating defects through variability reduction and improving customer satisfaction. Process variation is understood and brought under control by applying a powerful methodology (DMAIC) and sophisticated statistical and other tools.
A multinational healthcare services provider manufactures medical and surgical products; distributes products to healthcare facilities; and helps hospitals receive, store, and track medications and supplies.
Recently, the company initiated a push to become the industry leader. To do this, it implemented two methodologies:
Lean
The company initiated more than 100 small improvement projects, with the objective of improving the supply chain by removing waste and nonvalue-added steps. Within a year, this objective was met, with an overall cost savings of $10 million, improved quality, and greater customer satisfaction.
Six Sigma
Then, the company adopted Six Sigma to maintain the improvements and to address customer satisfaction and the defects that the initial improvements revealed. Within two years, the company realized over $25 million in savings and certified and deployed Black Belts and Green Belts across the organization to ensure continual improvement.
The phased implementation of Lean and Six Sigma enabled the company to:
- improve its supply chain by eliminating waste, increasing speed, and reducing inventory
- bring in statistical tools to maintain and control the improvements, to address the more pervasive defects in its processes, and to focus on customer satisfaction
Every organization is unique and may integrate a unique mix of Lean and Six Sigma tools and methods. However, nearly all organizations can profit by improvement in process efficiency and quality.
When planning an improvement initiative, an organization must examine its own needs and conditions in light of important implementation factors:
- the required time frame and financial commitment
- the primary problem to be addressed
- the organization’s ability to adopt a culture change
- the pervasiveness of the problem
Answering questions related to each factor can help you choose which elements of which methodology – Lean or Six Sigma – will apply to your organization.
Time Frame/Financial Commitment
Do you need a quick, relatively inexpensive strategy for reducing cycle time? Or is it feasible and worthwhile to apply rigorous statistical analysis to uncover the roots of the problem? Lean provides fast results, while Six Sigma requires a longer time frame.
Nature of The Primary Problem
What is the primary problem that you need to address? Is it waste and speed? Or is it defects and variation in processes? Lean reduces waste and increases speed. Six Sigma addresses defects and variation in processes.
Capacity for Culture Change
How quickly can your organization change in response to a new improvement methodology? Lean can be implemented while people are still getting used to a new way of thinking. Six Sigma requires a longer time frame.
Pervasiveness of Problem
How pervasive is the problem? Is it isolated and relatively simple to fix? Or does it permeate the entire process? Lean is useful for harvesting low-hanging fruit, problems that are relatively simple to fix. Six Sigma is used for addressing more pervasive problems.