Six Sigma Tools for DMAIC Process Improvement
Six Sigma is a management methodology that aims at eliminating defects and waste. It also helps to reduce variations in business processes to the barest minimum. However, to achieve effective results, organizations employ six sigma tools to drive systematic and strategic improvements in their processes. Also, six sigma professionals make use of these tools to implement improvements. Some examples of such tools are 5S, Value stream mapping, process map, root cause analysis and Kaizen events. 
When executing six sigma projects, the project team makes use of six sigma tools alongside a systematic model called DMAIC. DMAIC simply means Define – Measure – Analyse – Improve – Control. The DMAIC model for process improvements focuses on five major areas used in implementing six sigma projects.
Moreover, six sigma tools are important for management because the ultimate aim of every business is customer satisfaction. Quality improvement is key to achieving customer satisfaction. Customer satisfaction guarantees customer loyalty. In turn, customer loyalty will lead to increased referrals and recommendations.
Thus, this article will focus on:
- Six Sigma tools
- Six Sigma tools for quality improvement
- Six Sigma tools for DMAIC
Six Sigma Tools
The tools used in Six Sigma are essentially methods and techniques employed in implementing six sigma methodology. Six Sigma methodology focuses on eradicating defects that exist in business processes. Therefore, these tools are used to eliminate wastes, boost business profits and increase efficiency.
What is a Kaizen event?
Kaizen event is one of the six sigma tools businesses use to implement continuous improvements. Six Sigma professionals use kaizen events to observe, identify and perform incremental improvements in business processes. This tool incorporates the efforts of everyone involved in the business. In addition, the Kaizen event encourages teamwork and employs the joint efforts of employees and managers to achieve quality improvements.
Value stream mapping
Another six sigma tool used to drive quality is value stream mapping (Rother & Shook, 2003). Six Sigma professionals employ this tool during the Analyse phase of the DMAIC process. It shows how information and resources flow within the business process. Value stream mapping narrows down business processes to become swift and concise. Hence, it helps organizations to make the most effective use of their resources.
Furthermore, value stream mapping eliminates waste in business processes by removing wait times that exist between successive steps. Generally, this is one of the six sigma tools that help businesses identify value-enabling and value-adding activities. On the other hand, it also helps businesses identify and eliminate non-value adding activities.
Pareto chart
Pareto chart is a graphical six sigma tool that shows disparities in data. Professionals use this tool to measure process performance in order to determine the highest cause of defects in the business process. In addition, Pareto chart enables businesses to identify 20% of the cause of 80% of defects in their processes.
5S and 5-Why’s
These are other examples of six sigma tools. 5S system is a six sigma tool that helps to organize work processes in a way that removes waste and increases productivity. It employs 5S namely; sorting, setting in order, shining, standardizing and sustaining to achieve quality. On the other hand, 5Why helps to investigate the root cause of defects in business processes by asking ‘why’ questions.
Regression analysis
Similarly, regression analysis is one of the six sigma tools employed during process improvements. Six Sigma professionals use this statistical tool to analyse and estimate the mathematical relationship that exists between two variables. Businesses also use regression analysis to determine the relationship between a range of inputs and output variable.
Poka-yoke
Poka-yoke is a Japanese word that translates to “mistake proofing” (Productivity Press, 1986). Businesses use this six sigma tool to determine the causes of human errors in their processes and fix it. Likewise, six sigma professionals use poka-yoke used in the Control phase to DMAIC to make errors undetectable or impossible.
Failure Effects Mode Analysis (FMEA)
FMEA is a six sigma tool used to detect possible defects in a product, design, process or service before they occur. It is an acronym for Failure Effects Mode Analysis. The tool helps managers to thoroughly understand their business processes, identify threats and develop actions to counteract them.
FMEA is employed in the Analyse and Design stage of DMAIC. It is used in the Analyse stage to help identify products that are susceptible to failure. Similarly, in the Design phase, it is used to ascertain processes that require improvements.
Voice of the customer
Furthermore, the voice of the customer is one of the six sigma tools used to implement improvements. Businesses employ this tool as a proactive measure to gather feedback from customers about their needs, experiences and expectations. By doing so, businesses will be able to tailor their processes or products to meet and exceed customer expectations. Businesses can determine the ‘voice of the customer’ by engaging them in direct conversations or interviews. Also, they can organize group discussions or conduct online and offline surveys to gather feedback from their customers.
Six Sigma Tools for Process Improvement
Every business is made up of processes. A process is a flow of activities that modify inputs to produce output. Suppliers provide inputs in the form of resources, materials or information to the process. On the other hand, outputs are the end products generated by the process. Customers are the end-users of outputs.
Generally, the goal of every business is to satisfy its customers. Hence, six sigma tools for processes improvement will help businesses to generate quality outputs that will lead to customer satisfaction. However, to achieve quality, six sigma follows a systematic model for process improvements. The most popular six sigma models are DMAIC and DMADV.
DMAIC, DMADV & DFSS
DMAIC stands for Define, Measure, Analyse, Improve and control. It represents the five stages of quality improvement implementation in six sigma. Six Sigma professionals use this model to improve an existing business process that is performing below standard. Likewise, DMADV stands for Define, Measure, Analyse, Design and Verify. This method is sometimes called Design for Six Sigma (DFSS). Unlike DMAIC, six sigma professionals use this method to design new processes that will produce results to conform to six sigma standards.
Furthermore, six sigma tools for process improvement play a very important role in business. The tools help businesses reduce costs, improve performance as well as increase profits. They also ensure that business processes are analysed and enhanced to become efficient and achieve quality standards. Some examples of tools used to implement process improvements are flowcharting, cause and effect analysis and hypothesis testing.
Flowchart in six sigma process improvement
Flowcharting is a six sigma tool used for outlining and understanding business processes. A flow chart is also called a process flow diagram. A flowchart breaks down business processes into detailed activities, events and relationships. It gives a graphic representation of business processes. This six sigma tool reveals inputs, pathways and circuits, actions, decisions and outputs in the business process. Hence, flowcharting helps businesses to understand all the activities involved in their processes. As such, they can decide which activities to eliminate or introduce into the process.
Using fishbone or Ishikawa diagram in six sigma
Fishbone or Ishikawa diagram is one of the six sigma tools used during cause and effect analysis. Most problems associated with business processes can be resolved by determining all potential causes.
As a result, a cause and effect (fishbone) diagram helps to create a visual display of all the possible causes of defects in business processes. It achieves this by identifying the major areas in the process that could cause defects and result in a typical effect. For example, materials, methods, personnel, machine, environment and measurement. (Ilie & Ciocoiu, 2010 and Wong, 2011)
Testing hypothesis
This is a six sigma process that makes use of a range of statistical tools to analyse data. It consists of a null hypothesis (H0) and an alternate hypothesis (Ha). A null hypothesis indicates that there is no variance between two or more process outputs. On the other hand, an alternate hypothesis indicates that there is actually a variance between process inputs. The ultimate aim of hypothesis testing is to accept or reject the null hypothesis. Therefore, the alternate hypothesis is accepted if statistical evidence shows that the null hypothesis is false.
Six Sigma Tools for DMAIC
Tools for DMAIC are used for implementing quality improvements on already existing business processes. DMAIC is a continuous improvement cycle that means Define, Measure, Analyse, Improve and Control.
Define
The main purpose of the Define phase is to summarize the six sigma project plan. The six sigma team sets the goal for improvements and identifies the problem with the process. In addition, the team identifies customers and determines their needs using six sigma tool DMAIC. The project team employs a number of six sigma tools at the Design phase of DMAIC. Some of them are value stream mapping, SIPOC (Suppliers, Inputs, Process, Outputs, Customers), the voice of the customer and project charter. Project charter helps the team to define the scope, focus and direction of the project. It also helps them to map out the goal statement, time plan and estimated project benefits.
Measure
Furthermore, the main goal of the Measure stage of DMAIC is to gather data that covers the scope of the project. This includes determining the parameters for measuring process performance. After gathering data, the team analyses them with certain six sigma tools. For example, the team uses process maps to record the activities performed in the process. They also use capability analysis to assess the ability of a process to perform according to standards.
Analyse
The Analyse stage of six sigma DMAIC helps businesses to understand the root cause of problems. At this stage, the project team identifies the loopholes and ascertains the causes of errors. They also determine the opportunities available for improvements. The team uses six sigma DMAIC tools to determine the actual or potential cause of failures in the process. The Analyse phase of DMAIC is very important because the effectiveness of the project depends on the right identification of root causes. Common six sigma tools DMAIC used at this stage are root cause analysis, failure mode and effects analysis (FMEA), 5Why, fishbone diagram and hypothesis testing.
Improve
The Improve stage of DMAIC focuses on improving process performance by implementing improvements. The projects team determines possible solutions and methods of implementation at this stage. Furthermore, the team designs an improvement action plan that incorporates customer feedbacks and satisfaction. To ensure effectiveness and reduce risk, the team tests the action plan before they are implemented. Some examples of six sigma tools DMAIC used at this stage are Design of Experiment (DOE), kaizen events, poka-yoke and prototyping.
Control
The final stage of six sigma DMAIC is Control. At this stage, the project team puts control measures in place to maintain the improvements made. They use six sigma tools DMAIC like 5S, control plan, Statistical Process Control (SPC) and control charts to achieve this. A control plan is a written document of measures needed to maintain an improved process.
The major objective of the Control stage is monitoring and evaluation. The projects team monitors the progress of improvements and makes the necessary changes and/ or modifications. This stage is usually an adjustment phase. Businesses adjust their processes from current practices to new ones. Thus, it is necessary for the project team to provide training on new changes to management and employees.
Summary
Six Sigma tools are used to eradicate defects and waste in business processes. In addition, these tools are methods and techniques employed in implementing six sigma projects. These tools help businesses to increase profitability and efficiency and reduce costs.
Furthermore, project teams employ a number of tools when implementing improvements. Some examples are Pareto charts, value stream mapping, kaizen events, 5S system and 5Why. These tools help the team to achieve effectiveness and efficiency.
Every business is made up of diverse processes. Processes are all the activities that a business undertakes to transform inputs to outputs. The customer is the final user of outputs. Therefore, businesses must employ these tools for process improvements that help tailor improvements to meet customer’s expectations.
Nevertheless, project teams employ six sigma tools using a strategic and systematic model called DMAIC. DMAIC is an acronym for Define, Measure, Analyse, Improve and Control. These are the five stages required when implementing six sigma on an existing process. In order to achieve the objective of each stage, project teams deploy DMAIC at every stage of the project.
Conclusion
Tools for Six Sigma can be used to improve any type of business process. However, six sigma projects must pass through the five stages of DMAIC. Businesses that deploy six sigma tools in their processes will achieve quality improvements. Ultimately, continuous process improvements will help them attain customer satisfaction and loyalty.
For more about quality improvement methods, feel free to explore the following articles:
Six Sigma in Healthcare: Concept, Benefits and Examples
Lean in Healthcare – History, Tools & Examples
Total Quality Management Principles, Concept and Importance
Quality Improvement in Healthcare – Framework & Methodology
