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  1. 2 points
    Multicollinearity is a statistical phenomenon. It happens when several independent variables are highly correlated, However not perfectly correlated and In this situation we get regression results to be unreliable. In the above example, we could see how and to what extend does Consumer Price Index and Inflation Index can predict the rates. There is a considerable overlap between Consumer Price Index and Borrow Rate and Substantial overlap between Inflation Index and Borrow rate. Now, because there is a significant overlap between Consumer Price Index and Inflation Index themselves. It would be possible to predict with the unique non-overlapping contribution. Unique non-overlapping contribution of Consumer Price Index is Area c and Unique non-overlapping contribution of Inflation Index is Area b and Area a will be lost to standard error. Why Multicollinearity is considered as a problem? We would not be able to discriminate the individual effects of the independent variables on the dependent variable Further Correlated independent variables make it hard to make inference about individual regression coefficients and their effects on dependent variable. As a result, it is difficult to disprove Null Hypothesis, wherein actually the same should be rejected. Multicollinearity might not affect the accuracy of the model by a lot. But we might lose reliability in determining the effects of individual features of the model and that can be a problem when it comes to interpretability. How do we detect Multicollinearity? By using scatter plot or by using correlation matrix it would be possible to detect multicollinearity with regards to bivariate relationship between variables It can be detected based on Variance Inflation Factor or as popularly referred as VIF. VIF score of independent variable represents how well the variable is explained by other independent variables. When R2 value is close to 1, higher the value of VIF and higher the multicollinearity with the independent variable. VIF = 1 implies No correlation between independent variables and other variables VIF > 5, indicates high multicollinearity Diagnosis and Fix: Dropping one of the correlated features can bring down multicollinearity significantly Priority of dropping variable is based on the high VIF value Combining correlated variables into one and drop the others Points to remember before fixing: Removing multicollinearity will be a good option when more preference is given to individual features relatively to the group features that impact the focus variable Efficient corrective action to remove multicollinearity requires selectivity and selectivity in turn requires specifics about the nature of the problem.
  2. 2 points
    Andon System The origin of the “Andon” word in Japanese comes from the utilization of traditional lighting equipment employing a burning lamp made out of bamboo and paper. This “Andon” idea translated for manufacturing in Japan. The “Andon” became used as a proof to spotlight an anomaly (i.e., a flashing light). This signal would amplify potential defects in quality. When an error was suspected, an indication board would display a sign to the precise workstation having an issue. The signal event would also show that it stopped the system for the defect and expected the matter to be resolved. Ending an operation when an error was suspected originates from the initial Toyota Production System. The thought behind Jidoka is that by stopping the system, which helps to find a root cause against letting the defect move further down the road and be unresolved. Andon Cord Taiichi Ohno established a radical innovation when he went back to Toyota. At each step of the production line, he placed a rope called the andon cord. Ohno instructed the workers that if they saw a problem, they must immediately pull the cable, which might slow or stop the road so engineers, line workers, and even suppliers could confer and rectify the error. Electronic Andon Board Workshop leaders must be kept up on how smoothly things are moving into their workshops. The earlier they learn of abnormalities or other problems in their workshops, the earlier they will analyze the case and rectify it. Andon (alarm lights) makes an excellent tool for alerting workshop personal and other supervisors to identify problems on the factory floor. Andon is a unique lamp that illuminates issues within the factory. There are four types of andon given in the below figure. 1) Paging Andon Paging andon are often accustomed request supplies of parts for the assembly line. When parts are near to run out at a process, the operator sends out proof that lights the andon. Which also notifies those that operate the parts supply system. The suppliers’ quick movement around the factory in collecting and supplying parts is additionally called “mizusumashi” or beetle. There are two kinds of “whirligig beetle” techniques. One is that the “hire” method, during which a bunch of andon page the carts used for supplying parts. The different technology is that the “taxi” method during which dispersed andon page the carts. The below figure illustrates the “hire” method for paging andon. 2) Warning Andon Warning andon is mainly used on assembly lines and will differ depending upon the length of the road. On short assembly lines, people tend to use “aeroplane andon.” Like the attendee call buttons on passenger seats in commercial aeroplanes, each process within the production line has an emergency call button. When one in every one of these buttons is pressed, the andon board for the mechanical system lights up and shows which process’s button was pressed. Warning andon is mainly used on assembly lines and will differ depending upon the length of the road. On short assembly lines, people tend to use “aeroplane andon.” Like the attendee call buttons on passenger seats in commercial aeroplanes, each process within the mechanical system has an emergency call button. When one in all these buttons is pressed, the andon board for the line lights up and shows which process’s button was pressed. The following may be a detailed description of how “aeroplane andon” is used. The above form of warning andon configuration works tolerably when the mechanical system is brief enough to see all of the andon, processes, and operators. However, longer lines make it impossible to determine the full range and every one of its operators. During this event, the andon are lined up in an exceedingly centralised board, as shown in the figure. 3) Operation Andon Operation andon indicate machine operating statuses. When the device has been stopped, the operation andon shows the explanation for the stoppage. 4) Progress Andon Many assembly lines have short pitch times, like 1- or 2-minute tact intervals. When a range has such a brief tact time, the progress of operations is straightforward to look at just by monitoring the rhythm. It is tough to sense delays in lines with longer tact times, like 10 or 20 minutes. Progress andon enable line operators to measure the progress of their operations. Most progress andon is divided into ten equal sections. Still, the most ideal is to own the assorted stages of the operations correspond in a very level manner to the varied andon sections. When the progress andon board has changed within the case of conveyor lines, the limit switches can also detect the response.
  3. 2 points
    Andon! Everyone knows his child hood stories of Alarms given by elders about not doing something by some typical facial actions, sounds or even by showing something. It was to warn a child for not doing something else he may get hurt, he may get injured or there could be an accident. And it used to work; the child will remember all those actions, alarms and will not go near those things, will not touch and this way his life was saved. He continued the same thing when he was matured enough to teach other children’s. Really a very powerful technique of teaching, alarming and warning someone not to do something or in better way – To Do – “Not go near, Not to Touch etc.” In actual practice happening something wrong, variation in the process, small or major accidents are the part of a regular smooth, nonstop, productive process. We are in manufacturing sector so let us discuss about Manufacturing. § In manufacturing set up there are so many different processes running continuously and at a very high speed. These high speed processes are producing million tons of products or units in million. The pace is such a high; the variation in process will lead to heavy losses. § If there could be a small addition of Friction in heating of moving parts – it can lead to a bigger accident in near future. § If it is not monitored for its output, there could be wastage of resources. Today we are in most competitive, cost conscious, quality conscious, delivery conscious world and will never afford all above wrong things from happening. Fortunately we are in the most advancing era of technology, manufacturing techniques are evolving day by day and we have got a powerful tool at our help to save manufacturing process is – ‘Andon’ Andon – Is the Alarming, Notifying systems developed for managers, Supervisors, workers etc to highlight the health of the manufacturing (or any system) system. Lean production system is the boon to the modern age manufacturing, Andon is also one of the principle developed by lean only. An Andon system is the one of the principle elements of the Jidoka quality control method pioneered by Toyota Production system and therefore now part of the Lean Production approach. Jidoka – Is the automation with human touch or simply Intelligent Automation – It is the combination of Automation and human interference. As fully automatic systems are not cost effective to make it more cost effective and also to produce effective quality products human interference is essential. So – Andon – it gives the workers the empowerment to stop the production line, production machine if any abnormality is detected. There are so many techniques available by which a worker can detect rather come to know about the abnormal operation is the system. A. Audio Visual – With the help of different types of sensors system can detect any sort of abnormality happening in the system. It could be small displacement in the components, it could be more load (stress) coming on the components, it could be temperature variation. There are lots of digital gauges available and they keeps monitoring the system round the clock and keeps alarming the workers, supervisors or even managers about health of the system. With the advancement in automaton there are visual displays (HMI - Human Machine Interface) which gives the exact location where there is malfunction happening. With this alarm ( there is whistle with notification) the operator stops the machine and attend the challenge and avoids major losses. If the challenge on the machine or in the system is sever, even in that case machine stops with alarm and notification display. The operator, maintenance team can act immediately to save the major losses. All these notifications are coded and in SCADA system all those notifications are recorded systematically and gives the frequency of each notification along with the duration it took to rectify. This analysis gives way for Kaizen which leads in reduction in such uncertainty and eventually uniform uninterrupted production. Recently machine learning is also coming to our help by giving or poping notifications before taking any action which may lead to loss of data or any uncerytainty. B. Manual – In so many assembly lines there are provisions to stop the line if there is any abnormality found in any spares, shortages of spares etc. With this complete system gets alarm and work in down the line is adjusted accordingly. Simultaneously the concern department heads get the alarm to replenish the stocks. Manual systems though tedious, troublesome, still essential in some cases. Everyone knows the great Titanic disaster. There are few sensory alarms human eyes, nose and ears detect very rapidly and need immediate action. This is most effective activity only humans can do with inbuilt system. Advantages- The alarms, the moment malfunction or variation in system starts stops the system and major losses are saved. It helps to keep the wastages in control, saves cost and keeps profitability in control. The systematic records of abnormality gives ways for Kaizen Burst and scope for Continual Improvement which the only way to keep progressing towards growth. Once there is continual improvement, there is uniform production at specified productivity which is very essential to maintain oneself in today’s competitive market. It improves moral of the employees with safe working atmosphere. Less defects – less stops, less stops – happy employees, Happy employees – less accidents. Let’s continue to explore!
  4. 2 points
    What is a Venn diagram? John Venn who coined the Venn diagram in 1880 was an English mathematician, logician and philosopher. He also called them Euler diagrams after Leonhard Euler, who checked them out a century before. This is an extraordinarily flexible technique of combining circles useful for identify the contrast between overlapping areas of uniqueness. This representation of how groups relate to one another are generally called “sets”. There must be minimum two number of circles, and also the probability of maximum for many uses is 3. However, there can be more shapes in a diagram based on the number of sets and such a diagram can use unique shapes as per the below figures. Once the circles are interlocked, they reveal discrete areas (in which there’s no overlap). These again compared with the qualities of the overlap areas. Where there are three circles, the central area will show multiple overlapping characteristics. The volume of areas revealed should ideally be kept approximately proportional to their percentage of overlap, in order that the extent of the basic is visually representative. When to use a Venn diagram We often see Venn diagrams in mathematical contexts, but businesses and professionals also use these forms. In each case, the person creating the illustration wants to resolve a controversy, make a crucial decision, predict probabilities or visualize or understand how multiple sets or objects relate to at least one another. Instances when a Venn diagram might be useful in Business Market analysis: A Business Analysis Practitioner might use a Venn’s diagram for basic market research. While using two or more sets of data members within the meeting observe overlapping areas, as those areas contain the business’ target market. Competitor Analysis: A firm might use Venn diagrams to match themselves for their products to their competition. Most times, the business of using the Venn’s diagram may only use two sets of data to work out how they differ from the competition and find any similarities. This helps the business discover what advantages they have already got and specialize in areas where they will make improvements. Product Comparison: Alternatively, a business analyst may create an example with overlapping shapes to weigh the advantages of two or more work ideas. Within the same way that the business analyzes the market, a business analyst will weigh any differences and similarities two or more ideas share to work out which features of a product are the foremost desirable, as shown within the overlapping areas. Decision-Making: The same principles for analyzing two or more product ideas apply to a business’ general decision-making process. Advantages of a Venn diagram A Venn diagram provides the following advantages: It allows an analyst to visualize concepts and relationships between two or more data. It defines complex information into terms that an analyst can understand and represent easily. It helps an analyst to better keep information. Venn diagram symbols “∪ ” Union of two sets. An entire Venn diagram represents the union of two sets. “ ∩ “ Intersection of two sets. This type of intersection shows what items it shares between categories. “ Ac “ Complement of a Set. The compliment is that they don’t represent whatever in an exceedingly set. An classic example of Venn Diagrams; In a survey of the fast-food preferences of three people. We assign these three people as A, B, and C, showing which restaurants they enjoy. A three-circle diagram mostly covers every possibility that they’ll choose a restaurant by one, two, three or no respondents. Scores for Restaurant Survey Results: Restaurant A B C McDonald's 1 0 1 Wendy's 1 1 0 Burger King 0 0 0 In-N-Out 0 1 1 Taco Bell 1 0 1 KFC 0 0 0 A&W 0 0 0 Chick-fil-A 1 1 1 While creating the Venn diagram representing the results, we observed that in A∩B, we’ve Wendy’s because respondent A and respondent B both chose it. Few fast-food restaurants like Burger King, KFC & A&W remain outside the diagram but exist within the universe. Since all the three people have chosen Chick-fil-A, the intersection of all three represents A∩B∩C. So the final Venn diagram will represent in the below figure.
  5. 1 point
    Benchmark Six Sigma Expert View by Venugopal R The term “Andon” in Japanese means ‘paper lantern’. It is believed that such lanterns were used for providing a visual signal as well to communicate a message over a long distance. The term “Andon” was first used by Toyota for referring to any system or method used for signalling. Andon could be a signal in the form of visual, audio, symbolic or text to provide a notification to the concerned personnel in a workplace or even a public place, as a caution or information about a regular or irregular condition that may require attention or some action to be taken. Andon notification could be for notifying Management, Maintenance, Quality or any other stakeholder in an organization. Andons can provide ‘real-time’ feedback about a process. Incidentally, 'Andon cord' refers to a cord that was used in the manufacturing facilities, which could be pulled by the worker to alert any problem and even stop the line. Andons are very important to be integrated with various lean methodologies like the 5S, Poka Yoke and VSM. They have a wide application and are prevalent in many areas of our day-to-day life. Below are just a few examples of areas of Andon application: Production process – Number displays or Trend charts indicating the performance of a process. Andon warning lights in a production line are sometimes linked with sensors, PLCs and computer databases for automatic triggering of the signals. Floor layout – Yellow / Black markings on the floor indicating the pathways, storage locations, trolley parking locations. Material status identification – Identifying the status of materials, for eg. Waiting for inspection, Replenishment required, Accepted, Rejected etc by tags or color of bins. Cautions – Flashing lights to warn people about an equipment functioning, caution boards to indicate presence of high voltage, slippery surface etc. Office – Monthly stratified sales status against targets, BPM dashboards, Lean Six Sigma projects status, Training schedule and status. Control related – Visual indication of oil levels, battery levels, odometer of a car, Statistical control charts. Hospitals – Patient Admissions, Occupancy details, Healthcare personnel allocation and availability. Banks – Display of currency exchange rates, interest rates, customer token display. Identifying opportunities for Andons in any work place is a continuous improvement activity. The intent should be to identify the simplest possible method that would prove adequately effective and sustainable. Based on the feedback on effectiveness of usage, existing Andon systems need to be improved periodically.
  6. 1 point
    Sourabh Nandi has provided the best answer to this question by providing business applications of Venn Diagrams along with an example. Congratulations!
  7. 1 point
    Benchmark Six Sigma Expert View by Venugopal R ‘The Six Thinking Hats’ is a popular method of getting a team to think about a topic from multiple angles. Any brainstorming exercise needs good planning, facilitation and post-session work to derive the benefits of the time spent by a group of experts. Brainstorming, if allowed to happen as a ‘free for all’ exercise, will never provide any useful outcome. Various methods have been recommended for channelizing brainstorming efforts. The ‘Six Thinking Hats’ by Edward DE Bono is one widely accepted method to overcome some of the issues faced during a traditional brainstorming exercise. Genesis of the ‘Six Thinking Hats’ method. Each individual has got his / her characteristic and habitual way of thinking. Some will be optimistic by nature, whereas some will be cautious, and some others will be intuitive, creative and so on. With such different approaches of mind, based on individual behavioral characteristics, we would face clashes of interest, hurdles and passiveness during a brainstorming session. As per DE Bono’s thoughts, each of these characteristics are important and we need to look at a problem from all these angles before concluding upon the solution. He brought in six perspectives to be considered mandatorily during a brainstorming and related each on to a colour of a hat. These six perspectives are expected to largely cover encompass the variety of perspectives that could emerge from a group of individuals. What each coloured hat represents: White Hat – Facts: Focus on data, facts and information available or needed. Blue Hat – Process: Focus on managing the thinking process, next steps, action plans Red Hat – Feelings: Focus on feelings, hunches, gut feelings and intuitions Yellow Hat – Benefits: Focus on values and benefits; why something may work Black Hat – Cautions: Focus on difficulties, potential problems; why something may not work Green Hat – Creativity: Focus on possibilities, alternatives, solutions and new ideas How does it differ from traditional Brainstorming? In traditional brainstorming, the heterogeneity in the team-thinking at any point of time would cause conflicts on interests and will result in missing out valuable ideas from the multiple thought perspectives. There is bound to be dominance of few individuals and could result in bias towards their ideas. The participants whose perspectives could not be voiced or got overpowered, would feel their morale let down and will tend to have poor ownership on the final solution. By ‘wearing’ a particular colour of hat, all the participants force themselves to approach the problem in the perspective represented by the hat colour, at any given point of time irrespective of their natural inclination. This enables the entire team to address the problem in the same perspective at a given point of time. Room for dominance-based bias is reduced. By going through all the ‘colours’, the likelihood of anyone’s perspective getting left out is significantly reduced. This will enable to build an overall higher level of ownership on the accepted solution. Example case study: Let’s consider a situation, where an organization wants to decide whether they should purchase an expensive RPA tool. They use the ‘Six Thinking Hats’ for discussing and decision making. Please note that the points mentioned here are just for illustration and would not be exhaustive enough for an actual case. With the White Hat on, the team will focus on available data and the data required. They look at the number of automation opportunities, existing and likely to emerge in next couple of years. They look at the data on multiple options for RPA tools available and the comparative costs and features. They also look the past industry trends future prospects based on automation. With the Red Hat, the team will gather the intuitive opinions by the team members on different products available and the pros and cons based on hunches and individual opinions. They will also gather inputs as to what the team ‘feels’ about the need for automation, going for a third-party tool or developing it in-house. Wearing the Green Hat, the team encourages ideas for innovative thinking – alternate approaches to overcome their productivity issues or smartly modifying available software with internal expertise, or simplify the process with creative design thinking that could vastly reduce the number of steps involved. Other thoughts could be to leverage options offered through cloud computing. The Yellow Hat may introduce at this stage and focus on the tangible and intangible benefits of acquiring a RPA tool. They will look at the investment and ROI time frame. Other benefits could include improved accuracies and winning more customer good-will by providing faster and higher quality services. Another factor could be the enhancement in competitiveness. Black Hat may be brought in now – Concerns are raised on the credibility of the projections for automation. What if the technology gets obsolete faster than getting the ROI? Will it result in loss of jobs for employees? The Blue Hat is worn by the person facilitating the thought process, encouraging the ideas to flow and directing the switching of the thought process from one perspective to the next. Had they not followed the ‘Six thinking hats’ method, a few of the above points would have had a biased domination, quite likely around points 1, 2 and 4. Having explored the problem from all the perspectives the summary of the discussion will be comprehensive and would help the management team to take a very informed decision, with higher degree of ownership.
  8. 1 point
    Sudhir Gayakwad and Raj Saxena are the joint winners for this question. Also review the answer provided by Mr Venugopal R, Benchmark Six Sigma's in-house expert.
  9. 1 point

    Version 1.0.0

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    This zip file contains the study and exercise content for Lean Six Sigma Green Belt Training. You are requested to download and save this file in the laptop you will be using throughout the training. Note: It's important to download this file before the training to avoid any delay at the venue
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