Control Phase in Six Sigma……

What is Control Phase in Lean Six Sigma and How it differs from Pre Control?

THE SIGMA ANALYTICS

Purpose

To complete project work and hand off improved process to process owner, with procedures for maintaining the gains

Deliverables

  • Documented plan to transition improved process back to process owner, participants and sponsor
  • Before and after data on process metrics
  • Operational, training, feedback, and control documents (updated process maps and instructions, control charts and plans, training documentation, visual process controls)
  • A system for monitoring the implemented solution (Process Control Plan), along with specific metrics to be used for regular process auditing
  • Completed project documentation, including lessons learned, and recommendations for further actions or opportunities

Key steps in Control

  1. Develop supporting methods and documentation to sustain full-scale implementation.
  2. Launch implementation.
  3. Lock in performance gains. Use mistake-proofing or other measures to prevent people from performing work in old ways.
  4. Monitor implementation. Use observation, interaction, and data collection and charting; make additional improvements as appropriate.
  5. Develop Process Control Plans and hand off control…

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Pre Control in Lean Six Sigma ?

The Pre-control Technique

Pre-control is a control charting methodology that uses specification limits instead of statistically-derived control limits to determine process capability over time. Pre-control charting is useful in initial process setup to get a rough idea of process capability. Pre-control charting does not use continuous data found upstream in the process which is more in alignment with prevention thinking.

An easy method of controlling the process average is known as “pre-control.” Pre-control was developed in 1954 by a group of consultants (including Dorin Shainin) in an attempt to replace the control chart. Pre-control is most successful with processes which are inherently stable and not subject to rapid process drifts once they are set up. Pre-control can act both as a guide in setting process aim and monitoring the continuing process.

The idea behind pre-control is to divide the total tolerance into zones. The two boundaries within the tolerance are called pre-control lines. The location of these lines is halfway between the center of the specification and specification limits. It can be shown that 86%of the parts will be inside the P-C lines with 7% in each of the outer sections, if the process is normally distributed and Cpk= 1. Usually the process will occupy much less of the tolerance range, so this extreme case will not apply.

The chance that two parts in a row will fall outside either P-C line is 1/7 times 1/7, or 1/49. This means that only once in every 49 pieces can we expect to get two pieces in a row outside the P-C lines just due to chance. There is a much greater chance (48/49) that the process has shifted. It is advisable, therefore, to reset the process to the center. It is equally unlikely that one piece will be outside one P-C line and the next outside the other P-C line. This is a definite indication that a special factor has widened the variation and action must be taken to find that special cause before continuing.

Pre-control rules:

. Set-up: The job is OK to run if five pieces in a row are inside the target .

. Running: Sample two consecutive pieces

. If the first piece is within target, run (don’t measure the second piece)

. If the first piece is not within target, check the second piece

. If the second piece is within target, continue to run

. If both pieces are out of target, adjust the process, go back to set up

. Any time a reading is out-of-specification, stop and adjust

The ideal frequency of sampling is 25 checks until a reset is required. Sampling can be relaxed if the process does not need adjustment in greater than 25 checks. Sampling must be increased if the opposite is true. To make pre-control even easier to use, gauges for the target area may be painted green. Yellow is used for the outer zones and red for out-of-specification.

The advantages of pre-control include:

. Shifts in process centering or increases in process spread can be detected

. The percentage of non-conforming product will not exceed a pre-determined level

. No recording, calculating or plotting is required

. Attribute or visual characteristics can be used

. Can serve as a set-up plan for short production runs, often found in job shops

. The specification tolerance is used directly

. Very simple instructions are needed for operators

The disadvantages of pre-control include:

. There is no permanent paper record of adjustments

. Subtle changes in process capability cannot be calculated

. It will not work for an unstable process

. It will not work effectively if the process spread is greater than the tolerance

Risk Management Framework

 

RMF

How to Calculate Asset value (AV)

The asset value (AV) is calculated on the basis of range value.

Range value is the product of the values of “C”, “I” and “A”.

 Range Value = C * I * A

 In case all three parameters of (C,I,A) are not applicable for an asset and only one or two out of the 3 parameters are applicable then the range value is calculated as the product of the applicable parameters.  Once the range value is calculated for an asset, the asset value (AV) is obtained as per the defined table which maps the range value with the AV depending on the number of applicable parameters.

How to Calculate “C”

Conf_Parameters

How to Calculate “A”

avail_para

How to Calculate “I”

intig_para

Net Promoter Score (NPS) Calculation and concept……

NPS concept understanding

THE SIGMA ANALYTICS

Have you ever liked a company so much that you’ve told your friends about it?

The Net Promoter Score system uses one basic question to measure customer loyalty:

“How likely is it that you would recommend our organisation to a friend or colleague?”

There are many formulae to understand customer’s opinions, such as the Customer Satisfaction Score (CSAT) system, but the NPS system is intended to go beyond testing how satisfied a customer is with a company: it’s designed to test whether someone likes a brand enough to recommend it to others.

In other words, the person isn’t merely “satisfied” with the company – by telling others about the brand, the person is effectively marketing the company’s services.

Although there are pros and cons to NPS, numerous research studies have shown that the NPS system also correlates with business growth.

Studies by the Harvard Business Review have found that companies…

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Net Promoter Score (NPS) Calculation and concept……

Have you ever liked a company so much that you’ve told your friends about it?

The Net Promoter Score system uses one basic question to measure customer loyalty:

“How likely is it that you would recommend our organisation to a friend or colleague?”

There are many formulae to understand customer’s opinions, such as the Customer Satisfaction Score (CSAT) system, but the NPS system is intended to go beyond testing how satisfied a customer is with a company: it’s designed to test whether someone likes a brand enough to recommend it to others.

In other words, the person isn’t merely “satisfied” with the company – by telling others about the brand, the person is effectively marketing the company’s services.

Although there are pros and cons to NPS, numerous research studies have shown that the NPS system also correlates with business growth.

Studies by the Harvard Business Review have found that companies ranging from banking to car-rental companies show higher income when they improve their Net Promoter Scores.

So, if you’re looking for a more scientific way than just relying on online reviews to understand your brand’s strength, the NPS is a straightforward system to use, and one of its big benefits is that it allows you to benchmark your company’s results against others in your industry.

The Way NPS formula works

Just as the main question of the Net Promoter Score sample survey is fairly simple, the Net Promoter Score calculation system is too. At first glance, it may seem rather complicated, but we’ll show you how to break it down and make figuring out your Net Promoter Score an easy process.

The Net Promoter Score Scale

To get started, customers are asked to rate their likelihood of recommending a company to a friend or colleague by using a 0-10 point scale:

The number on the scale that a customer chooses is then classified into one of the categories: “Detractors,” “Passives,” and “Promoters.”

Score breakdowns:

0 – 6: Detractors

7 – 8: Passives

9-10: Promoters

You can think of the NPS system as similar to a four-star system on an online review, but the NPS scale gives you a broader way (and a more accurate method) to measure customer’s opinions.

How to calculate Net Promoter Score ?

Let’s suppose you’ve sent out an online poll with the NPS question and the 0-10 scale and you’ve received 100 responses from customers. What do you do with the results? Is it as simple as averaging the responses? Well, not quite. But it’s almost that easy.

The NPS system gives you a percentage, based on the classification that respondents fall into – from Detractors to Promoters. So to calculate the percentage, follow these steps:

·  – Enter all of the survey responses into an Excel spreadsheet.

·  – Now break down the responses by Detractors, Passives and Promoters.

·  – Add up the total responses from each group.

·  – To get the percentage, take the group total and divide it by the total number of survey responses.

·  – Now subtract the percentage total of Detractors from the percentage total of Promoters – this is your NPS score.

Let’s break it down:

(Number of Promoters – Number of Detractors) / (Number of Respondents) x 100

Example: If you received 100 responses to your survey:

10 responses were in the 0-6 range (Detractors)

20 responses were in the 7-8 range (Passives)

70 responses were in the 9-10 range (Promoters)

When you calculate the percentages for each group, you get 10%, 20% and 70% respectively.

To finish off, subtract 10% (Detractors) from 70% (Promoters), which equals 60%. Since an example Net Promoter Score is always shown as just an integer and not a percentage, your NPS is simply 60. (And yes, you can have a negative NPS, as your score can range from -100 to +100.)

Once You’ve finished your Net Promoter Score Calculation. Now what?

So you’ve sent out the NPS survey sample to your customers. You’ve compiled the results and run the numbers. You now have your Net Promoter Score number – maybe it’s a 52. Is that good or bad?

Well, like many things in life, it’s really all relative. If your competitors have NPS numbers in the high 60s, you’re probably going to try to work out where your brand could improve. On the other hand, if your competitors all have scores in the low 40s, you’re doing just fine.