Suresh Jayaram

Dear Jerry, The control limits (UCL & LCL) are based on +/- three sigma limits away from the center (average). These control limits are used to determine if a process is in control or not. Only if the data is normally distributed will 99.73% of the data lie within the three sigma limits. So, we expect that most of the data will fall within the control limits. If data points don't fall here, then in all probability, the process has gone out of control. For other types of data distributions, the % of points that lie within the three sigma limits will be different. Let's say only 80% of the data lies within the three sigma limits. In which case, even if the process is in control, the control limits will indicate a lot of false positives where it will show that the process is not in control even if it is in control. Other thoughts on this question? SJ>

Dear Iyer, I presume you are talking about the last point regarding data analysis on my original article. What I meant was that if you are a manager and understand how to work with data and are comfortable with preliminary statistical measures, you are more apt to find out if your subordinates did a good job with analyzing the situation at hand and are they making the right recommendations. You could check that the data that they have picked is representative of the entire population, it is truly random, it is not biased etc. so that the right conclusions can be drawn from the data. A manager who is not familiar with Six Sigma may just accept the analysis of their subordinates and will not know if wrong conclusions are being made from incorrect data analysis. Hope this helps. SJ

Dear Manik, I agree that Top Management support is the number one Critical Success Factor for success of Six Sigma within a company. With respect to your project, are you working on a project that is strategically important for the company? Is there a pain area for your managers that is keeping them awake at night and if you are able to solve that problem, then the manager can sleep peacefully. One of the reasons for lack of support is the selection of the wrong project. If managers are not supporting Six Sigma, maybe you can try using some of the change management techniques to turn them around. Sometimes even this may not be successful in some cases, so the only option left would be to work on your own time in the evenings and weekends to complete a Six Sigma project for your own learning and benefit. PS: This open forum is for beginners who are new to Lean and Six Sigma. Please post this question in the private forum for past participants where you can get feedback from other past participants who may have other suggestions to help you with this issue.

Let's delve into the soft side of Six Sigma a bit... Six Sigma helps develop leaders for an organization because: a.) Six Sigma resources are trained to attack problems and solve it the right way by relying on facts & data. You don't want leaders to make decisions using intuition - just shooting from the hip. b.)Six Sigma resources work on projects and hence they know how to lead teams and get things done in a team atmosphere. c.) Six Sigma resources are familiar with and can compute financial implications of their decisions/projects. d.) Six Sigma resources usually work on projects that are crucial to the company's success - hence they get exposed to the areas that are important for the company. e.) Six Sigma resources focus on customer satisfaction - a trait which will enable them to be successful in other areas. f.) Six Sigma resources understand how to deal with resistance and effectively manage change. g.) If a Leader is trained in Six Sigma, it will be hard for others to fool him/her with improper data analysis. What are your thoughts on this topic?

I would like to invite discussion on the following observation: "In manufacturing, the actual machine or equipment cycle time is usually a lot smaller than the overall lead time for the product/service from order to delivery". If we were working on a manufacturing project cycle time or lead time reduction, then we should not be focussing our efforts (Six Sigma projects) in reducing the machine processing time but instead look at all the activities that happen before the manufacturing process (from order taking to supplier delivery of components) and after manufacturing (from transportation to inventory to stocking at the customer's warehouses). For example, the average time to make a car by GM, Ford, Toyota is in the range of 30 hours. However, we all know that if we were to go to a dealer and request for a car with specific features it takes a lot longer than 1 day to get it. This is one example where benefits that can be realized by working on transactional processes can yield a lot bigger benefit than working on the manufacturing processes. What do you think?

Let's say you are working on a project to reduce Turn Around Time (TAT). The current TAT has an average of 5 minutes with a standard deviation of 2 minutes. The process does not have a lower specification limit but it does have an upper specification limit of 4 minutes. Would you set the goal for your project to reduce the average TAT from 5 minutes to 4 minutes? What is wrong with this picture? How would you establish a target/goal for this project?

Dear Suresh, That is a very good point. It is one of the concepts also taught in Lean "Genchi Genbutsu" which means "Go see for yourself". If a CSR is not familiar with the product or service it would be very hard to answer all the questions the customers may have. One way is to have the CSRs walk in the customer's shoes and experience the product/service for themselves - if it is too expensive to do this in real life, at least they should have good training / simulation to experience the product or service. In summary, it is not the person (CSRs) to blame but the process that is put in place. SJ

Dear Pankaj, Kano Analysis is a tool that can be used to understand how the different features you provide on your product/service are viewed by your customer. According to Kano, there are three types of needs a) Basic Needs Performance Needs c) Excitement Needs Basic Needs are things that customers usually don't talk about but they expect it in the product. If it is there, they don't pay much attention to it, but if it is not there, then they get dissatisfied. Example is the presence of a driver's seat in the car. Performance Needs are things that provide more satisfaction to the customers the more you provide them this feature. Example is the fuel efficiency in a automobile. Higher the better. Excitement Needs are those that that customers don't even know about or expect that you are going to provide to them. If you give them this feature, then they are really excited and are willing to pay a premium for this feature. Example is a car that can drive itself (not available yet, so let's think about a car that can park itself). So, in a DFSS project, if we are designing a product or service, we need to definitely provide the basic needs, provide as much performance needs as we can afford, and try to include excitement needs to outsmart the competition and charge a premium for our products/services. Other comments on this thread?

Project Management is the application of a set of principles, methods, tools, and practices that enable the project manager to plan, organize and deliver projects with acceptable quality on time and on budget. Project Management is typically undertaken for medium to large projects where this is a substantial risk of project failure such as cost over-runs, delays, poor deliverables etc. Project Management (PM) works with a known set of resources and plans for the activities required to deliver the project. The biggest issues in PM are identification of the right activity durations due to resource constraints, managing risks, getting the resources to execute per plan, communication of issues and project progress, and generally managing expectations of all key stakeholders. PM can benefit from application of Lean by stabilizing and standardizing the processes used to complete activities, elimination of NVA activities, deploying pull type systems to manage work-in-process inventory, making progress visual, and making the work flow through the company to reduce overall lead time for project completion. PM can benefit from application of Six Sigma by launching Six Sigma projects to identify root causes of why projects are not being delivered on time and fixing these problems. PM can benefit from the rigours of Six Sigma in the area of establishing baselines, appropriate project metrics that include leading and lagging indicators, using tools to come up with the best solution, putting controls in place to sustain solution etc. The above was a very brief write-up and I am sure there are several other issues not mentioned above. What are your thoughts on this topic?

Dear Samar, There are a lot of factors involved in getting a good job - including educational qualifications, experience, attitude, recommendations, emotional intelligence, etc. In order to get a job, you have to compete with others who are also applying for the same position. When companies don't know your skills and they have to hire you based on your resume and interview. It always helps to have knowledge and skills that are valuable for the employers. Having a Six Sigma Green Belt training and certification tells an employer that the candidate understands the importance of quality and has the requisite tools to help with business process improvement. This can be a differentiator if others don't have these skills or at least it would not be negative in case you are competing with others who have these skills. Regards, SJ

The video link was a good introduction to Lean. Thanks for posting it. Some of the Lean Manufacturing tools are rather simple to understand (such as 5S) but one has to be cautious when deploying some of the more advanced tools like Value Stream Mapping (VSM). Some companies have totally destroyed their processes by doing the wrong things in their future state VSM. I feel that hardest part of Lean is deploying and sustaining it within a company. It involves a change in culture of the company and it takes a lot of persistent effort to change the behaviours & attitudes of people. SJ

Dear Samar, In order to proceed with Six Sigma training, you will have to sign up for the Green Belt class. There are several training providers out there, but if you want to learn from the best, you will have to train from Benchmark Six Sigma. Benchmark Six Sigma currently does not have any public training courses in Rajasthan, so you may have to travel to one of the eight cities across India in which Benchmark Six Sigma offers training. Would that be a possibility for you? You can access the training calendar link by clicking on https://www.benchmarksixsigma.com/calendar/ The duration of the course is 4 days (Wednesday - Saturday) or Weekend format (Sat-Sun followed by another weekend Sat-Sun). The course fee information can be obtained by either calling one of the phone numbers listed at: http://www.benchmarksixsigma.com/contact-us Hope this helps. Let me know if there is anything else. Best Regards, SJ

Dear Manik, There is a gray area between GB and BB projects. Usually, a project is called a GB project when the scope is limited, the impact of the project is limited to say within a functional area, the benefits are small, and the project duration is also rather small (couple of months). Otherwise, it would be a BB project. The methodology and tools used are rather similar between GB and BB. Though, a BB may use slightly more advanced tools to attack complex issues. In your case, looks like the scope is rather large - could impact multiple departments / functions / people. Hence, it looks like a BB project. I am not sure of the content of your GE GB DMADV training. If you share the topics that were covered in your GB DMADV, I can let you know what additional material is covered in BB DMADV class. Best Regards, SJ

Dear George, With respect to the first question (#11 above), yes you should use 98% if your historical process is performing at 98%. With respect to the second question (#12 above), technically you are right, it is a hypergeometric distribution. However, when the population size is large, then it is usually convenient and recommended to work with the binomial distribution. Ref: http://www.quantitativeskills.com/sisa/distributions/hypghlp.htm Best Regards, SJ

Dear Yatin, In my opinion, BI analyzes facts & data and makes predictions on market trends, sales expectations etc. If BI identifes a potential problem or opportunity for improvement, it would be ideal to start a Six Sigma project to attack the opportunity and reap the benefits. Hence, both BI and Six Sigma should be closely integrated where BI feeds ideas for Six Sigma projects and Six Sigma ensures that problems are solved in the best possible way. Other thoughts? SJ

Dear Shradha, Both Lean and Six Sigma are business process improvement methodologies. They each have a slightly different approach to meet their goals. Some differences in their practical application: Lean: Train 100% of the workforce on simple tools such as 5S, Kaizen etc and make continuous improvements to processes every day. Six Sigma: Train about 25% of the organization of advanced statistical problem solving tools and ask them to fix larger problems with unknown root causes or solutions within the companies. Different companies have different take on which is better. Some companies feel Lean is better while others feel Six Sigma is better. Of course, there are those that deploy and benefit from both of them - which is an option I would recommend. If you are involved in business process improvement activities, you should learn and use both the approaches.

Dear Manik, Since you are trying to setup a PMO, the Best Six Sigma approach would be to use DMADV. Once it is setup, you could use DMAIC to make further improvements if required. Some of the ideas to consider: a) Coming up with the right PMO charter (sponsorship, expectations, metrics, cycle time, goals, scope etc) RACI analysis to highlight roles & responsibilities of different members c) Understand the VOC to design the best PMO that meets customer needs. Use of QFD to determine measurable metrics. d) Explore alternatives and develop a comprehensive solution (Facilities, Human Resources, Technology) e) Simulation of the recommended processes to optimize solution f) Risk mitigation, pilot, and implementation activities. A PMO developed using the above ideas will be the Best Six Sigma approach and will have the best chance of success within the company.

Dear Pankaj, There may be several means to automate inspection in a process. Some of these options may be expensive but it may be possible to devise novel methods of inspection based on the physics that need not always be expensive. You could get some ideas by inviting different suppliers of automation instruments to see if they have any better ideas. Benchmarking with your competitors or similar processes in other industries may also provide ideas for "cheaper" ways to deploy automation in a process. SJ

Dear Vishwanath, Are you talking about Project Y ? Not sure what you are referring to when you say project measures. SJ

Dear Pradeep, You need to have some criteria within your organization on what makes a good Six Sigma GB project. You can use your senior managers to rank the criteria and determine the importance ratings. Some criteria that are usually found are: Linkage with company strategy Benefits that can be realized Time/resources required to complete projects Availability of right resources/data etc You can then evaluate each GB project against the pre-established criteria and come up with an overall score. You may also want to plot them on a benefit/effort matrix to help with the selection process. Not all decisions can be quantitatively based - so you would also need to form a committee of select managers within the company who would be responsible for selecting the right GB projects. It would be a good idea for the committee to meet periodically - at least on a quarterly basis to select projects and keep them ready for launch. For every GB in the organization, you need to have at least 1-2 projects ready in the pipeline ready for launch.

Dear Sumit, Some of the Lean tools we use to do root cause analysis in the Analyze phase are 5 Why's, Pareto analysis, PDCA, etc. Of course, you could use the standard set of Six Sigma tools to validate your root causes for a Lean Six Sigma project. Comments? SJ

Dear Nitin, If you are working with continuous data and based on the sample you want to infer what is happening to the population mean, you would use the mean formula. If you are working with discrete data (defects/defectives), we usually work with proportions. Example: If you want to compute the average height of a person in India, then you would use the mean formula. If you want to find out what percentage of the population is greater than 6 feet, then you would use the proportion formula. Other comments? SJ.

Dear George, With respect to 11 & 12 above, 11. Yes, Raosoft calculations are inaccurate. They do not consider the power values when they recommend a sample size. You can use Minitab and show that if you set the power of test at 50%, you will get the same answers as recommended by Raosoft. You don't have to do the manual calculations by hand. Of course, you are welcome to use the excel spreadsheet that I provided if you don't have access to Minitab. This is not the same as 50% response accuracy. That refers to the null hypothesis Ho: p = 50% (where p stands for proportion and not the p-value). 12. If sampling is done with replacement, then it follows a binomial distribution and if sampling is done without replacement, then if follows a hypergeometric distribution. So, the question you need to ask is does the % accuracy numbers change as you sample the data. This is a moot point usually, when the population sizes are very large and both of these distributions will give you similar answers. As you have correctly pointed out, the formulas are using normal approximations anyway. I also derived my formulas that I used in the excel spreadsheet using the normal approximation. Best Regards, SJ

Sometimes people tell us that getting to 3.4 defects per million (DPMO) is very difficult in manufacturing. Most manufacturing processes have a process capability target of around 1.33 or at best 1.67. This corresponds to a target of 4 to 5 Sigma Level. First of all, just because we have a Six Sigma project, it does not mean that every project needs to end up at 3.4 DPMO. Where 3.4 DPMO corresponds to a Six Sigma process. A project that can improve performance from 2.3 Sigma Level to 3.2 Sigma Level is still a Six Sigma project. The biggest challenge in manufacturing is to identify the critical tolerances that are really important from a functional point of view for the product. Usually, on a drawing, there may be several tolerances and not all of them may be important. Setting the right tolerances on them (not too loose and not too tight) becomes very important. I find that these values are sometimes derived not based on any analysis but based on what was done historically. The specs get copied from version to version and it becomes very hard to trace the reasons why the specs were put there in the first place. Setting too tight of specs without reason may be one reason why getting to Six Sigma is tough in manufacturing. What are your thoughts? Do you have a different point of view on this topic?

Hi Kapil, DMAIC is applicable for situations where you have a chronic issue rather than for situations when you are developing a process from scratch. If you have several project ideas, pick a project that gives you the biggest benefit (returns) and which can be completed with the smallest resources (time, capital expenditures etc). Let's look at UAT: What are your main concerns with User Acceptance Testing in the past? Is it the cost of such a testing, the time it takes to complete UAT or the number of defects observed at this final stage or the number of cases that pass through UAT but still cause dissatisfaction at the customer end? The data you collect on the above for your specific company, may guide you to one area you can focus on to get rid of those problems in the future and you can use a Six Sigma process to identify the root causes of the problems and come up with solutions to get rid of them. SJ