DMAIC, PDCA, Lean 6 Sigma

DMAIC?(an acronym for?Define, Measure, Analyze, Improve, and Control)?(pronounced d?-MAY-ick) refers to a data-driven improvement cycle used for improving, optimizing, and stabilizing business processes and designs. The DMAIC improvement cycle is the core tool used to drive?Six Sigma?projects. However, DMAIC is not exclusive to Six Sigma and can be used as the framework for other improvement applications

DMAIC is an abbreviation of the five improvement steps it comprises: Define, Measure, Analyze, Improve and Control. All of the DMAIC process steps are?required?and always proceed in the given order.

Define

The purpose of this step is to clearly pronounce the business problem, goal, potential resources, project scope and high-level project timeline. This information is typically captured within project charter document. Write down what you currently know. Seek to clarify facts, set objectives and form the project team. Define the following:

• A problem
• The customer(s),?SIPOC
• Voice of the customer?(VOC) and?Critical to Quality?(CTQs) — what are the critical process outputs?

Measure

The purpose of this step is to measure the specification of the problem/goal. This is a data collection step, the purpose of which is to establish process performance baselines. The performance metric baseline(s) from the Measure phase will be compared to the performance metric at the conclusion of the project to determine objectively whether significant improvement has been made. The team decides on what should be measured and how to measure it. It is usual for teams to invest a lot of effort into assessing the suitability of the proposed measurement systems. Good data is at the heart of the DMAIC process.

Analyze

The purpose of this step is to identify, validate and select root cause for elimination. A large number of potential root causes (process inputs, X) of the project problem are identified via root cause analysis (for example a?fishbone diagram). The top 3-4 potential root causes are selected using multi-voting or another consensus tool for further validation. A data collection plan is created and data are collected to establish the relative contribution of each root causes to the project metric, Y. This process is repeated until "valid" root causes can be identified. Within Six Sigma, often complex analysis tools are used. However, it is acceptable to use basic tools if these are appropriate. Of the "validated" root causes, all or some can be.

• List and prioritize potential causes of the problem
• Prioritize the root causes (key process inputs) to pursue in the Improve step
• Identify how the process inputs (Xs) affect the process outputs (Ys). Data are analyzed to understand the magnitude of contribution of each root cause, X, to the project metric, Y. Statistical tests using p-values accompanied by Histograms, Pareto charts, and line plots are often used to do this.
• Detailed process maps can be created to help pin-point where in the process the root causes reside, and what might be contributing to the occurrence.

Improve

The purpose of this step is to identify, test and implement a solution to the problem; in part or in free of all whole. This depends on the situation. Identify creative solutions to eliminate the key root causes in order to fix and prevent process problems. Use brainstorming or techniques like?Six Thinking Hats?and?Random Word. Some projects can utilize complex analysis tools like DOE (Design of Experiments), but try to focus on obvious solutions if these are apparent. However, the purpose of this step can also be to find solutions without implementing them.

• Create
• Focus on the simplest and easiest solutions
• Test solutions using?the plan-do-check-act?(PDCA) cycle
• Based on PDCA results, attempt to anticipate any avoidable risks associated with the "improvement" using the?Failure mode and effects analysis?(FMEA)
• Create a detailed implementation plan
• Deploy improvements

Control

The purpose of this step is to embed the changes and ensure sustainability, this is sometimes referred to as making the change 'stick'. Control is the final stage within the DMAIC improvement method. In this step; Amend ways of working; Quantify and sign-off benefits; Track improvement; Officially close the project; Gain approval to release resources.

• A?Control chart?can be useful during the Control stage to assess the stability of the improvements over time by serving as

1. a guide to continue monitoring the process and

2. provide a response plan for each of the measures being monitored in case the process becomes unstable.

• Standard operating procedures?(SOP's) and Standard work
• Process confirmation
• Development plans
• Transition plans
• Control plan
• Benefit delivery

PDCA?(plan–do–check–act?or?plan–do–check–adjust) is an?iterative design?and management method used in business for the control and continual improvement of processes and products.?It is also known as the?Deming?circle/cycle/wheel, the?Shewhart?cycle, the?control circle/cycle, or?plan–do–study–act?(PDSA). Another version of this PDCA cycle is OPDCA.?The added "O" stands for?observation?or as some versions say: "Observe the current condition." This emphasis on observation and current condition has currency with the literature on?lean manufacturing?and the?Toyota Production System.?The PDCA cycle, with Ishikawa's changes, can be traced back to S. Mizuno of the?Tokyo Institute of Technology?in 1959.

Lean Six Sigma is a synergized managerial concept of Lean and Six Sigma. Lean traditionally focuses on eliminating the eight kinds of waste ("Muda"), and Six Sigma focuses on improving process output quality by identifying and removing the causes of defects (errors) and minimizing variability in (manufacturing and business) processes.

Lean Six Sigma uses the?DMAIC?phases similar to that of Six Sigma. The five phases used in Lean Six Sigma aim to identify the root cause of inefficiencies and work with any process, product, or service that has a large amount of data or measurable characteristics available.

The different levels of certifications are divided into belt colors. The highest level of certification is a black belt, signifying a deep knowledge of Lean Six Sigma principles. Below the black belts are the green and yellow belts. For each of these belts, level skill sets that describe which of the overall Lean Six Sigma tools are expected to be part at a certain belt level are available.?The skill sets reflect elements from Six Sigma, Lean, and other process improvement methods like the?theory of constraints?and?total productive maintenance. To achieve any of the certification levels, a proctored exam must be passed that asks questions about Lean Six Sigma and its applications.

Waste (Muda) is defined by?Fujio Cho?as "anything other than the minimum amount of equipment, materials, parts, space, and workers' time, which are essential to add value to the product".

Different types of waste have been defined in the form of a?mnemonic?of "downtime":

• Defects: A defect in a product that is declared unfit for use, which requires the product to be either scrapped or reworked, costing the company time and money. Examples include a product that is scratched during the production process and incorrect assembly of a product due to unclear instructions.
• Over-production: Over-production refers to products made in excess or before it is needed. Examples include creating unnecessary reports and overproduction of a product before a customer has requested it.
• Waiting: Waiting involves delays in process steps and is split into two different categories: waiting for material and equipment and idle equipment. Examples include waiting for authorization from a superior, waiting for an email response, waiting for material delivery, and having slow or faulty equipment.
• Non-Used Talent: Non-Used Talent refers to the waste of human potential and skill. The main cause is when management is segregated from employees; when this occurs, employees are not allowed to provide feedback and recommendations to managers to improve the process flow, and production suffers. Examples include poorly trained employees, lack of incentives for employees, and placing employees in jobs or positions that do not use all of their knowledge or skill.
• Transportation: Transportation is the unnecessary or excessive movement of materials, products, people, equipment, and tools. Transportation adds no value to the product and can lead to product damage and defects. Examples include moving products between different functional areas and sending overstocked inventory back to an outlet warehouse.
• Inventory: Inventory refers to excess products and materials that are unprocessed. It is a problem because the product may become obsolete before the customer requires it, storing the inventory costs the company time and money, and the possibility of damage and defects increases over time. Examples include excess finished goods, finished goods that cannot be sold, and broken machines on the manufacturing floor.
• Motion: Motion is the unnecessary movement by people.?Excessive motion wastes time and increases the chance of injury. Examples include walking to get tools, reaching for materials, and walking to different parts of the manufacturing floor to complete different tasks.
• Extra-processing: Extra-processing is doing more work than is required or necessary to complete a task. Examples include double-entering data, unnecessary steps in production, unnecessary product customization, and using higher precision equipment than necessary.