Adding Value to Six Sigma with Lean Tools

Many Six Sigma practitioners are discovering the advantages of incorporating value-focused Lean thinking into the DMAIC roadmap. Whether or not you label this initiative “Lean Six Sigma,” you can still benefit from adding Lean methods and tools to your Performance Excellence projects.

Below we introduce several Lean tools that add the most value to Six Sigma, and explain where they fit in the DMAIC process.

Value Stream Map (VSM)

Perhaps the single most valuable Lean tool is the Value Stream Map (VSM). More than just a glorified process map, it’s a roadmap to success. Not only does it map the process flow, it also documents the people, inventory counts, queue times, cycle times and lead times for the process. In addition, it allows you to identify value-added process steps (essentially those that the customer would pay for), so you can work on eliminating non-value-added steps (the ones that do not add value to the end product or service).

As such, a VSM can be useful during project definition, as well as during any number of points along the DMAIC roadmap. In the Define and Measure phases it can take the place of a high-level process map, especially if the primary metric is time-based. During Analyse and Improve, you can investigate eliminating the non-value-added steps identified on the VSM to improve the process. You can even create a “Future-state” VSM that documents the desired process flow.

And, of course, you’ll want to update the VSM during the Control phase to reflect any changes in the process.

Takt Time

Takt Time is a formula that helps validate your measurement system.

Often used during the Measure phase of DMAIC, Takt Time helps you translate your customer requirements (demand) into your process requirements (capability), which is important for any type of improvement.

For example, if your process suffered from a high rate of defects, your proposed solution might be a longer cycle time. But you would need to know if extending the cycle time would allow the process to still keep pace with customer demand.

Understanding Takt Time can also keep you from producing more than the customer demands. Such overproduction is a waste of time and resources (and possible space and transport if you’re dealing with physical inventory). Producing the right amount at the right time is one of the keys to Lean thinking.

Eight Types of Waste

Speaking of waste, Lean specifies eight types of waste that can be eliminated from processes to improve lead time (the time required to complete a single iteration of the process) and flow (the process running evenly at full utilisation). In addition to overproduction, waste includes waiting, rework, motion, over processing, inventory, transportation and intellect.

During the DMAIC Analyse phase, a review of each type of waste can reveal opportunities for improvement. Often, these wastes are merely a symptom, a result of larger issues including process variation and overburden.

5S

Many Lean tools come into play during the Improve phase, but 5S is one of the most applicable to any environment. The term “5S” stands for Sort, Store, Shine, Standardize and Sustain. Each of these tasks can help improve the process and create a desired future state by eliminating waste through organisation, cleanliness and standardization in the workplace.

Mistake Proofing

Mistake Proofing is the technique of changing the process to prevent mistakes from occurring. As you can imagine, this is a valuable tool during the Control phase. There are a variety of mistake proofing methods you can employ, but the important thing is to look for ways that the improvements you are implementing can be done incorrectly, and then implement ways to prevent this from happening.

More Information

Lean and Lean Six Sigma are hot topics, which means anyone who wants to learn more has a variety of resources to choose from. BMG recommends several books on the subject, including:

Lean Thinking - A bestselling classic by James Womack and Daniel Jones, two internationally respected management analysts. The authors provide an overview of Lean principles backed by numerous real-world examples.

A Team Leader's Guide to Lean Kaizen Events - This guide is for leaders of Lean Kaizen events who are looking for a step-by-step process for conducting a successful Kaizen Event.

The Complete Idiot's Guide to Lean Six Sigma - Released in April, this book provides detailed roadmaps for Lean Six Sigma execution at both the project and organisational levels. It includes 175 helpful graphics and 100 specific examples of how Lean Six Sigma tools and techniques are used.