Six Sigma Interview Questions and Answers

Q1 : What are the different levels available in Six Sigma?
A : Six Sigma is nothing but a process improvement methodology where the root cause of the errors are identified and ultimately helps in improving the overall process. So when it comes to Six sigma level, one has to check with DPMO score. If the accuracy of the process gets to a level where it has only 3.4 defects per million opportunities.
Below, is the list of defects per million which are catered towards a single level:
690,000
308,537
66,807
6,210
233
3.4

Q2 : What is the main role of executive leaders or executive management in terms of implementing six sigma team?
A : Well, these are the individuals who will be responsible for driving initiatives to make sure their product quality and processes are optimized to a profitable level where the entire team is being productive with fewer operations costs incurred. So most of the time, the executive leaders will be CEO or Board of director members etc. The main motto of these individuals is to make sure that they deliver a quality product to the customers and make sure they are satisfied.

Q3 : When was Six Sigma was developed and who was the inventor?
A : So the six sigma process was developed by Motorola to make sure that their products are measured in terms of highest quality and the year it was invented in 1986.

Q4 : What is meant by Lean Six Sigma?
A : Well, a lean six sigma is nothing but a methodology which involves the entire team effort to bring them in the change in terms of performance improvement by identifying the waste and the variance reduction. So in conjunction with the lean six sigma process and eliminates 8 different kinds of wastes, they are as follows:
1. Defects
2. Overproduction
3. Transportation
4. Inventory
5. Motion
6. Extra Processing

Q5 : What is the main difference between lean and six sigma?
A : The main difference between lean and six sigma is that lean methodology focuses on waste reduction within a process flow. Whereas, six sigma process focuses mainly on variation analysis and variance reduction.

Q6 : What does DFSS stand for in six sigma process?
A : DFSS stands for Define for Six Sigma.
This process is actually involved in designing or redesigning the service or a product from scratch. One of the cases where the project is following DMAIC methodology, it goes into DFSS project because of the designing related tasks.

Q7 : What is a Pareto principle?
A : A Pareto chart is used to display the data and the tool is based on the underlying concept of Pareto principle. It is often called as 80/20 rule. Using this rule, it will help the team to focus on specific tasks and issues which might have a greater impact if they are not looked into at the initial stages.

Q8: What is Top-down approach in six sigma process?
A : The top-down approach is one of the processes within Six Sigma implementation. So usually this type of approach is in line with the business strategy and customer needs. But it has one of the major disadvantages is that the scope is very broad and at the same time it is difficult to be executed in a specified amount of time. As per the industry standards, the six sigma projects are executed and completed in the time span of 3 to 6 months.

Q9 : What are the popular myths or misunderstanding about Six Sigma process?
A : The popular myths or misunderstanding about six sigma process is as follows:
** Six Sigma process is defined only for reducing defects.
** Six Sigma process is actually used for production or deployments of a project
** Six Sigma is just a training and has no implementation in the day to day life.
** Six Sigma process cannot be applied to engineering activities.

Q10 : What are the quality management tools and methods that are used in Six Sigma process?
A : They are many third-party tools that can be integrated with Six Sigma process to achieve the process efficiency. The methods that six sigma follows are:
1. DMAIC: Stands for Define, Measure, Analyze, Improve, Control
2. DMADV: Stands for Define, Measure, Analyze, Design, Verify
Q11 : Explain in detail what is meant by DMAIC six sigma methodology?
A :  DMAIC stands for Define, Measure, Analyze, Improve and Control. Within this process, it is an improving system for all the existing process where they identify whether there needs to be any process improvement and look for it on regular basis to achieve the ultimate process efficiency.
So basically, this process to execute it has 5 different phases where the entire functional flow or the process is evaluated on different parameters which eventually results in the optimized process flow for better and concrete outcome.

Q12 : What is the difference between load test and performance testing?
The difference between load testing and performance testing is as follows:
A : Load Testing:
1. Load testing is nothing but a testing process where the load limit is beyond the client has required for. This would help us understand whether the application can handle a certain limit.
2. Load testing is about how well the application or the program is behaving and how many concurrent users are able to login to the application without any problem.
Performance Testing:
1. Performance testing is all about having more stress on the system checks and also the overall application and system performance during the stress conditions.  In a sense, performance testing is nothing but a superset of the load test.
2. Performance testing includes the load testing and as well as the stress testing.

 Q13 : What are the benefits of six sigma process to the organization and for the individual practicing it?
A : The benefits of six sigma process are as follows:
>> Helps the organization to reduce to a level where they can eliminate the errors
>> Works towards improving the business processes
>> Works towards betterment of Quality Assurance
>> This process can be applied throughout the business environments, applicable for all the markets
>> Makes sure that it comes under compliance
>> Helps the individuals to build skills and turn into leaders
>> Have attractive salaries for individuals having this skill
>> Quality assurance and quality management

 Q14 : How to develop a SIPOC process map?
A : SIPOC stands for Suppliers Input Process Output Customers.
A process can be defined as a series of consecutive steps and activities that are executed in a timely manner to get a definite output.
The SIPOC process map is very important for identifying the following elements:
1. How the current processes are operating
2. How the processes are modified and improved
3. How the improvement is carried out or implemented with the next phases of DMAIC

Q15 :  So how does the cost of six sigma implementation is estimated by the organizations?
A : Well, the cost of six sigma implementation is estimated by the organization in different ways and few of the popular ones are listed below:
1. The cost associated with six sigma implementation can be paid out from the direct payroll of the company and identify the individuals who were involved in this process full time and paid accordingly
2. This is an indirect payroll policy where the individuals are identified and payout based on activities like data gathering, measurements, and discussions with the product owners etc.
3. This is purely a consultative approach, where the consultants will be paid based on the number of hours they have to spend to train and mentor the team
4. This is completely a different approach towards six sigma process. The payout can happen based on the process improvisation.

Q16 : What do you mean by FEMA?
A : FEMA stands for Final segment of the Measure Phase.
So basically it promotes the cause of preventing defects before even they occur. So in a sense being proactive and making sure that are no known defects within the process. Within FEMA process they generally include the possible defects and rate them accordingly in three different ways, they are:
1. The likelihood of something might actually go wrong
2. Ability to detect a defect.
3. Defect severity level
If the defect severity is considered to be low then the user are do not have to spend more time in terms of validating the process.

Q17 : What are the three steps for Root cause analysis?
A : The three steps for Root cause analysis is:
1. The Open step: This is the initial step where all the team members are gathered together and do a brainstorming session on all possible scenarios.
2. The Narrow step: During this phase, all the possible explanations and scenarios are narrowed down to an extent considering our current sigma performance.
3. The close step: During this phase, the project team will validate all the narrowed down list of explanations for the current sigma performance.

Q18 : What is a data collection plan?
A : A data collection plan is nothing but a plan which is used to collect the necessary data. So within this plan, the following aspects are covered.
1. What type of data needs to be collected or gathered is analyzed in the data collection plan
2. What are the data sources for the data is analyzed in the data collection plan
So the main reason to collect data is to understand the current process and portray possible improvement suggestions. The data can be collected from three different primary sources they are as follows:
1. Input: input is nothing but where the data is generated
2. Process: the process is nothing but the execution steps where the factors like efficiency, time requirements, cost, defects are taken into consideration for process improvements.
3. Output: it is a straight measurement of the efficiency.

Q19 : What is the difference between the Six Sigma DMAIC and DMADV methodologies?
A : The DMAIC methodology, instead of the DMADV methodology, should be used when a product or process is in existence at your company but is not meeting customer specification or is not performing adequately.
The DMADV methodology, instead of the DMAIC methodology, should be used when:

  • A product or process is not in existence at your company and one needs to be developed
  • The existing product or process exists and has been optimized (using either DMAIC or not) and still does not meet the level of customer specification or Six Sigma level

Q20 :  Name some of the Quality Management tools in Six Sigma
A : There are a number of quality management tools. Some of them are cost-benefit analysis, CTQ Tree, SIPOC analysis, COPIS analysis, and Taguchi methods. (Name at least five)

Q21 : What level of understanding do you have regarding the statistical tools?
A : This should reflect the skills that you have regarding the statistical tools with respect to Six Sigma. Be honest while answering the question.

Q22 : What is the process sigma calculation?
A : Process sigma is a measure of the variation in a process relative to customer requirements.

Q23 : What are X bar and R charts?
A : They are a set of two charts, which is the most commonly used statistical process control
procedure used to monitor process behaviour and outcome over time.

Q24 :  What is the symbol of Six Sigma?
 A : Six Sigma has a greek symbol which is ”sigma”. It is the standard deviation utilized to measure the variation in the process.

Q25 : What is the 1.5 sigma shift?
A : The 1.5 sigma shift adjustment takes into account what happens to every process over many cycles of manufacturing.