Throughout the multitude of diverse Lean manufacturing principles out in the world, there’s one common trait that unites them all: the need to push consistently for improvement and progress. The DMAIC cycle is no different in its drive toward improving business models, design, and processes through data. These days, the DMAIC is most closely associated with Six Sigma, and borrows from nearly every Lean concept out there. Six Sigma’s goal is to eliminate the chance of defects in a production system down to 3.4 defects per million cycles, and it uses DMAIC as a path toward achieving that goal.
In this article, we’ll outline what the DMAIC cycle is, explain the theories/theorists that gave birth to DMAIC, and how you can implement this Lean manufacturing concept to reduce waste and increase efficiency.
Breaking Down the DMAIC
The DMAIC cycle is an acronym for the following steps: define, measure, analyze, improve, and control. All of these steps are crucial to the process, as they provide unique and necessary roles in improvement and optimizing your facility’s production.
Let’s take a closer look at this methodology.
- Define: this refers to defining the system itself, which includes customer expectations, goals for projects, etc. Well-defined goals that are specific and clear in their vision and expectations mean products come out clear, consistent, and with high-quality results.
- Measure: this stage dictates that measuring the various steps of the process and collect and save the data. In Six Sigma, this data is often called the “as is” process capability.
- Analyze: With the data collected from the Measure stage, the next step is to analyze the collected information and determine what it means. This stage is most illuminating—this is where you see causal relationships, which allows you to then take all the necessary actions to ensure all conditions, special circumstance, any other factors into account. This gives you a full, comprehensive picture of your process and all of its flaws.
- Improve: Take the current process and use data analysis to form a plan for improvement. Techniques like design of experiments, poka yoke, and mistake proofing are great paths toward successful improvement. Experiment with various alternative production techniques to establish the new process capability.
- Control: finally, the last step in the cycle calls for a measure of control to ensure there are no inconsistencies/potential for defects are eliminated from company processes. This the last step, but it’s a vital one; without control, the changes made in the first four steps of the DMAIC cycle will not be sustained.
The Other Option
In Six Sigma, there’s an alternate to the DMAIC cycle. This is called the DMADV (sometimes called the DFSS, which stands for Design for Six Sigma):
- Define: design goals that align with customer needs/your business strategy
- Measure: quantify characteristics of your product that are critical to quality (CTQ). Measure product capabilities, production processes, and risks
- Analyze: collect those measurements, then analyze them to develop and design alternatives to the current production processes.
- Design: If necessary, create improved processes that agree with the analysis and measurements determined in previous steps.
- Verify: set up trials, test theories, and experiment with processes to make sure your findings are correct.
The two paths to Six Sigma are similar, but have enough differences to make each model unique. Chose the that best fits your team.
DMAIC cycle’s beginning is directly linked to Six Sigma’s. In the eighties, Motorola had a quality control problem. After a particularly heated managers’ meeting, the COO of Motorola John F. Mitchell decided to tackle the issue head-on by hiring two consultants, Bill Smith and Dr. Mikel J. Harry. Through hard work and a lot of collaborative thinking, the two came up with Six Sigma concept for quality control improvement. The DMAIC borrows from the theories of W. Edwards Deming, Joseph Juran, Philip Crosby, Kaoru Ishikawa, and Genichi Taguchi. From these theorists, Smith and Dr. Harry were able to build a foundational blueprint to eradicating defects in production.
Let’s take a look at some of those thinkers/ideas that informed Six Sigma and DMAIC.
- Philip Crosby — one of the first Americans to make quality control a top priority, Crosby measured quality by the cost of non-conformance. In other words, it was Crosby who convinced American manufacturers that quality was a crucial factor in retaining or losing customers. He began measuring quality by its cost of non-conformance, or, in other words, the comprehensive cost of defective products.
- Kaoru Ishikawa — this theorist and University of Tokyo professor was responsible for resuscitating the practice of quality circles and for creating many Lean concepts that helped post-war Japan become a manufacturing leader in the years after World War II. Using W. Edward Deming’s ideas as a foundation, Ishikawa came up with many guidelines and concepts for smarter production and quality management, such as the influential fishbone diagram.
- W. Edward Deming — You’d be hard-pressed to find a Lean concept that didn’t start with this influential engineer and thinker. Often considered the godfather of Lean manufacturing, Deming’s Plan Do Check Act (PDCA) model was the basis for the DMAIC cycle. Both models break down each stage into specific, manageable actions. Deming’s was a proponent of models that were both scaleable and sustainable, and DMAIC cycle values these principles as well.
How to Get Started with DMAIC
Use the Tools
Getting started with Six Sigma can feel as daunting as being asked to climb a rock face without any rope or equipment. Luckily, there are a number of QA tools you can use to complete the DMAIC cycle.
Tools like process mapping and value stream mapping reveal the path your product takes from raw material to your customers’ hands. In taking such a comprehensive look at your production processes, it’s easy to see where waste is occurring, where most defects occur, etc.; therefore, you have an educated picture of processes and can more easily define what it is you’d like to focus on.
Tools Like Fishbone diagrams and 5 Whys help you get to the root of your production problems. CTQ trees help companies translate customer needs into actual production specifications, which means you’re not wasting time on features customers don’t care about, and instead give resources to the things customers desire. Overall equipment effectiveness (OEE) is a formula for assessing the productivity of your facility, and its accuracy can even pinpoint the resources spent on rework from defects.
These are the tools that make the DMAIC cycle possible. Use them wherever you can to get a complete picture of your company’s quality issues, and to help find solutions to your quality problems.
Get Help from an Expert
Six Sigma’s principles are simple, but the work that goes into quality control and management can be complex and overwhelming. There are Six Sigma consultants out there who’ve dedicated huge amounts of their professional careers to Six Sigma. These experts hold Six Sigma belts—the certification system used to measure the Six Sigma expertise. Here’s a quick break down of the Six Sigma belt system:
- White Belt - Not an official certification, the white belt signifies a beginning on the path toward Six Sigma certification.
- Yellow Belt - This signifies a base-level of knowledge regarding Six Sigma. Yellow belts generally function as the worker bees on Six Sigma projects.
- Green Belt - Green belts are seasoned workers in Six Sigma. They can be trusted to supervise smaller projects and oversee data collection and some analysis.
- Black Belt - Like in karate, earning a black belt is a significant milestone. Individuals with black belts are usually in charge of large-scale projects like directing Six Sigma programs.
- Master Black Belt - Being a master black belt is the highest certification one can earn. Very few hold this certification, and it takes years to get it. Those with this level of expertise general work for large, global operations.
If you don’t want to hire a consultant, consider enlisting one of your workers in becoming a belt holder themselves. There are many training programs that help individuals earn their Six Sigma certifications. Having an expert on-site ensures that new team members will always be trained in Six Sigma, and that Six Sigma will become a part of your company’s culture.