DMAIC

Revision as of 11:14, 21 February 2019

Abstract

The DMAIC-framework is a Six Sigma tool used to secure the best practice in planning and executing an engineering project. When you as a project manager work with advance engineering projects, whose purpose is to improve and stabilize a current process, it is advantageous to apply the DMAIC-framework. The abbreviation DMAIC stands for the following:

• Define the project and its limitations so the scope of the project is well-defined. If not, it is almost impossible to measure and improve, if you do now know where to start.

• Measure the current state to understand the extent of the problem and define the desired end state. If this isn’t done, your project can not be rated as a failure or success, if you don’t have a target.

• Analyze the reason to the problem and come up with a range of possible causes. The best solutions will proceed to the improve phase.

• Improve the current state with the recommended solution or solutions found in the analyze.

• Control if the desired end state is reached. If not, start over again.

This article will describe which tools, you as a project manager, are recommended to apply for each section, and the pros/cons of the usage. It is important to emphasize that the phases can overlap each other, and an example will be presented in the article. By using this framework, the project manager secures that he or she does not overlook anything and accidentally jump to conclusions.

The framework is also suitable as a structure for major technical project as bachelor- and candidate projects. Since the lector and censor typically know about the framework, they have already outlined your project roughly, and it will give you an advantage in creating the famously red threat. An example of this will be presented in the article.

Why to use the framework and what to expect from it

When you as a project manager uses the DMAIC framework, is it to achieve a well-tested solution that will eliminate your problem discovered in the define phase. The framework is designed to be used on a well-established process with minor difficulties. If your process is not in control and the variation is high, LEAN is a more suitable framework or ideology to follow.

To perspective this to everyday life, imagine that you drive your car on a road. It is said, if you neither has LEAN nor Six Sigma, you will end up in the ditch now and then. If you have LEAN implemented, you will keep the car on the road. If six sigma, which DMAIC belongs to, is implemented, you will be able to drive on the center stripe.

If your process is in control but not quite delivering the desired yield, then please read on – this article is for you!

The tools in depth

This section will describe each tool in the order presented in the table above, to secure a common understanding of each tool. When to apply a curtain tool, pleas look at the table above.

With/without

It is important to define what tasks that is included and what is not. If this is not done prior, the project will fast intervene. By using this tool, a well-structured overview with tasks are presented. SIPOC. Visual process diagram. The abbreviation SIPOC stands for suppliers, inputs, process, outputs, and customers. This tool is used to get an overview over the process you are focusing on. Questions like:

• Who supplies the process inputs?
• What inputs are required?
• What are the major steps in the process?
• What are the process outputs?
• Who receives outputs?

This requires the user to show interest and investigate the process, and thereby gathering information and knowledge of the current situation.

VOC Tree

The abbreviation stands for Voice of Customer Tree. This tool is similar to the fishbone/root cause analysis, but with another focus, as it finds solutions on problems presented by the customer. E.g. cellphone-costumers are not satisfied with the duration of the battery life. A solution to this would be fitting the new cellphone with a larger battery, or re-program the system so it is more efficient and not uses as much as before.

Walk the process

This tool demands the project manager to walk the process which gives an understanding of the value stream. By doing so, some of the operators might give you some information or direct you in a curtain direction of your problem understanding, you might have missed. The tool is often used in combination with some of the others like SIPOC and the fishbone diagram.

MSA study

The abbreviation stands for Measurement System Analysis. The tool is used to investigate how uncertain your measuring system is. For clarification, the measuring system is the one you as a project manager uses to collect data during the work with the DMAIC model. If the overall percentage is below 10 %, it is rated valid. Between 10-30%, it is not recommended, but usable if the better solution is not possible to receive due to e.g. cost, knowhow, etc. Above 30 % is considered unacceptable. Factors influencing the MSA can be: calibration, fixturing, skills, materials, number of samples, temperature, humidity etc.

Pareto analysis

This tool may also be known under the nickname “80/20”-rule, since a rule of thumb says, that 80 % of the registered errors on a machine are due to 20 % of the number of causes. This helps the project manager to prioritize where he or she should focus first. Be aware of the following two things:

• The pareto analysis can be used over an over. After the usage of the analysis, when a solution has been implemented, a new cause is the main root-cause to 80 % of the errors.
• The percentage is guiding, so in some occasions, the 80 % might be 70 or 90, and the 20 might be 10 or 30. This is not something to be worried about or basis for changing tool, since the percentage is guiding.

Time series plot

This is a simple tool to present data found in the measurement or analyze phase with the time as the value on the x-axis, and your results on the y-axis. Some examples of that could be the yield from a production line, the height or diameter of the produced project over time. Using a time series plot makes it easy for the user to present their discovery, instead of numbers in a table.

Defect concentration diagram

The tool is a visual representation of where the errors occur. This could be used on the product, e.g. if the task was to improve the strength of a product, and 50 crash tests was completed. Each damage would then be marked on a drawing of the product, to investigate where the weakest link was. This tool is recommended to be used together with the pareto analysis, so the error causes can be ranked. The tool can also be used on a production line, then you will mark the causes on a drawing of the line. The procedure will be the same, and you will end up with an understanding of where your product or production line is failing most often.

Brainstorming

The tool is the most common used when creating new ideas. This require each person invited to present their best idea without filter. Therefore, there is some ground rules to be followed:

1. No criticism or negativity is allowed. This will kill the motivation and creativity at the participants, and the brainstorming is ended before it even started.
2. Relaxed atmosphere. This secures that each member does not feels that he or she is prevented from presenting their idea.
3. Quantity is preferred over quality. In this stage, every idea is equally good. The more the better, because in the next step, the selection starts.
4. Add to or expand. Discus the presented ideas and try to expand and add to the ones you think is possible and will suit your project focus.

In the end, you will end up with a lot of causes to the problem or a lot of ideas that possibly will eliminate the root causes found in the analysis.

Fishbone diagram

After completion a brainstorm for the causes to the problem, it is recommended to organize your findings in a fishbone diagram. The fishbone has a set of pre-defined categories that each finding should be placed in. The categories are machinery, method, material, people, measurement and environment. Try then to ad a cause to the previous cause, e.g. category people “operator mistakes”. A root-cause to this could be “lack of training”. The lack of training increases that one of the operators makes a mistake. If the problem has many aspects, you would end up with a lot of different potential root-causes. It is suggested to arrange the root-causes in a pareto analysis.

RCA3

The abbreviation stands for Root Cause Analyze three way. This tool or data-collection idea secures that you do not solve the symptoms, but the root cause. The number 3 is related to the number of methods to collect data on the same phenomenon. An example of this RCA3 could be: asking operators how they experience the variation in the production line, investigating the machine documentation on critical components and performing a measurement study of the production line. This is an example of three different data collections, to investigate the same topic. If all three analysis shows the same result, the result is very believable, since three different methods, confirms the same phenomenon.

5S

5S stands for the five steps in creating a workplace without superfluous items and documents. People tends to pile up their work and moving on to the next project, before sorting the table. The tool can be used, and is wrongly called a “cleaning tool”, to create systematic and an organized workplace. The 5S’ are (the English translation are shown in the parenthesis):

• Seiri (Sort). Remove not needed documents as outdated Post-It notes and completed work.
• Seiton (Streighten, Set). Organize your remaining stuff, like placing the pencils in a container.
• Seiso (Shine, Sweep). Clean the area to secure a clean start for the standardize phase.
• Seiketsu (Standardize). Mark on the table where to place your stuff, like the tape dispenser, pencil container and Post-It’s. You can use tape or colors to identify where to place your work articles.
• Shitzuke (Sustain). Make it a routine to place the things back where they belong.

This tool will help you creating an organized workplace where you do not have to clean, since your desk is always spotless.

Work instruction

The tool is a reminder to emphasize that regardless how good the training received from your supervisor or manager is, a work instruction is needed. This secures that the practice taught is not forgotten and easily communicated to e.g. new workers. Best practice. The previous tool, work instructions, should be based on best practice. When used correctly, it presents the best possible practice available to the employees. To achieve best practice other tools such as walk the process and brainstorming with the employees should be used. This forces the project manager to involve the employees to secure to take their personal experiences into account. If this is not done, the eight of the lean waste types (Non-Utilizied Talent) can be identified.

Checklists

When ever a process is completed, a control of the executed work is preferable. This could be in form of a second person control of the completed work. In some firms, specially the pharmaceutical industry, traceability of the products is required. One of the actions securing the traceability is, the products are produced following a production instruction, which works as a checklist. After production the e.g. medicine, a quality department normally reviews and control that everything is fulfilled and within the requirements. This tool minimizes the likelihood of mistakes.

Decision matrix

This tool is used to secure, that a curtain solution is chosen among others from a factual point and not from personal preferences. These can be created in many ways, but the things they have in common are the following:

• Defined factors that are weighted from e.g. 1-5. If a thing is rated important, this will receive the rating 5 and if not, the rating of 1. Factor could be “driving ability” “safty” and “horse power” if the decision was to choose a car.
• Possible solutions rated from 1-5 according to each factor e.g., when staying in the car analogy, the brand Volvo will score high on the safety, and a Ferrari high on the driving ability and horsepower.

The sum of the weighted factors multiplied with the solution rating will give an overall value. The solution with the highest value, will be the most preferable to implement. By using this tool, something as subjective as selecting something, can almost be done objectively. Therefore, this tool helps minimize the personal bias.

RPT analyze

The abbreviation stands for Result, Probability and Time. This is three important focus points to bring to the project owner to motivate and engage him or her. These themes are very common on a so called “one pager” delivered to the project owner or the project sponsor. An additional topic to the RPT is C (cost) which is one of the most, if not the most, factor focused on. By applying this tool, your one pager to the project sponsor will cover the most important findings in your project.

SPC

The abbreviation stands for Statistical Process Control. This tool is used during the production to secure, that if process exceeds from the pre-set acceptance limits, according to the specifications of the parts, the process can be stopped in time, before producing defects. In the ideal world, this would not be necessary, but errors do occur. By applying this tool, it is possible to change the process before crating defects and minimizing the scrap cost of the defective products and most important, avoiding costumer complaints.

Week- and monthly-reporting

When your project is implemented and shows the desired results, it should be presented to the managers and the project sponsor. It is recommended to organize weekly meetings in the beginning to confirm that the process is improved. After a few weeks, hopefully with good results, monthly report-meetings should be just fine.

Histogram

This tool is, like the defect concentration diagram and fishbone diagram, a visual representation. The histogram is recommended in the analyze phase to track the current state, and in the end when the future state is achieved. This gives an easy understanding of the situation, without you as a project manager needing to say much.

Related models

The PMI standards for project management, A guide to the Project Management Body of Knowledge (PMBOK guide) 6th Edition (2017)) presents the standard of project management, which is like the structure of the DMAIC model. The topics are the following (the correspondent DMAIC phase is in parenthesis next to the PMBOK headline):

• Initiating Process Group (Define)
• Planning Process Group (Measure/Analyze)
• Executing Process Group (Improve)
• Monitoring Process Group (Control)
• Closing Process Group (Control)

Another model very similar to the DMAIC model is the PDCA-model presented from the lean toolbox. The abbreviation stands for Plan, Do, Check, Act. This is an iterative and more simplified version of the DMAIC model. As said previous on, the lean framework is more suitable when the process is not in control. That is why the continues improvement is required with the A (act).

This shows that some frameworks look alike but have a different perspective and goes in depth with some areas and leave others behind.

To wrap up, the DMAIC model is used to secure the best practice Defining, Measuring, Analyzing, Improving and Controlling an engineering project, that focuses on improving and stabilizing a existing process.