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Case Study 2

Introduction

We are starting to see our problem. As a production team, we are looking for consistency in output. We were looking for the conformance of a grouping of product to specification. The reality is that for each grouping of product, say the 16-ounce fill line, we have four separate machines, two separate operators, and a significant number of variation causes from machine to machine. What we wanted to see was a simple view of reality – a common population grouping of 16-ounce fills, one bunch from one process having great conformance characteristics. What we ran into was the buzz saw of a typical reality - a varying collection of 16-ounce fills from some very different ensembles. We have four bunches from four processes having dissimilar conformance characteristics.

We had been very vocal and aggressive in pushing our personal view of workplace reality (which was very wrong) and now need to recover work group confidence and support.

Having started the team approach, we need to continue the team approach. The current problem is our problem not their problem. If we change the ground rules and dismiss or limit the team’s participation or ability to contribute, we will undermine and erode any sense of teamwork we have created.

We have been considering bringing in a specialist/consultant, but we don’t want to undermine the teams’ authority or prerogatives. If the teams decide that a specialist/consultant is a possible resource or if they can be led to decide that a specialist/consult is a possible resource, we will heartily concur and make all the arrangements.

The reason we didn’t initially start with a specialist/consultant was our simplified and mistaken assumptions that some equipment peaking and tweaking, some minor process maintenance and repair, and a general facility cleaning and some paint would be all we needed. Reality 101: Our assumptions didn’t lead us astray; our limited knowledge of reality did.

Larry has left the 16-ounce fill line day crew for an opening in maintenance that offered more money and more varied working conditions. The maintenance position was openly announced in the facility and competitively bid. Of the four applications for the position Larry was the best qualified. We were hoping that Larry would glean all he could from Charlie about the 16-ounce fill line, its characteristics, adjustments, limitations, maintenance and repair, and that he would pass this general and specific knowledge on to the other fill lines. We took Larry aside and offered him equal money and some additional benefits if he would stay on the 16-ounce line for the next six months but he refused. He knew the other facility personnel knew that he had been selected for the maintenance position and that if he stayed on the 16-ounce line for any additional time, it would be obvious that “some kind of deal” had been struck.

It is company policy to interview personnel when they move from position to position to summarize and recap their views on how thing are going and what things could be improved. Larry stated that the best thing about the 16-ounce fill line was Charlie. Larry said that he and Charlie didn’t socialize, they didn’t hold conversations, they didn’t share personal information, but if anything happened and Larry needed or could use a hand, Charlie was there. Larry also admitted that Charlie did much of the set up and adjustment on Larry’s two 16-ounce fill machines. Larry said he learned a lot from Charlie but because the facility hasn’t gone into full production yet, there still was much more to learn.

Larry’s replacement on the 16-ounce line is Betty. The announcement of the job opening created by Larry’s move was posted at both the manufacturing and the fill facilities.

Betty is a twelve-year employee from our manufacturing facility who began as a tool room clerk, moved to a tool inventory and maintenance position, and for the past four years was been a second shift set up and maintenance technician. She is characterized as being a fast learner, a competent technician and a focused individual. She has no fill line work or process experience.

Situation

We are still focusing on the 16-ounce fill line because the 16-ounce fills are demonstrating the best conformance to specification. They have the highest consistency and the lowest variation between machines. The 8-ounce, 16-ounce, 32-ounce, and 64- ounce lines all have identical fill machines of basically the same age. The material distribution network that brings product to the fill machines is basically the same, and the line control devises are basically the same. What is it that creates great consistency on the 16-ounce line?

Let’s review the 16-ounce line fill specification. We require 16.0 +/- 0.10 ounces on each and every fill. We would like to see exactly 16.0 ounces of fill each time but process variables and the environment interact together to cause some degree of variation in every fill. Some variation is so slight as to be unnoticeable; some variation is so significant as to cause concern.

Here is what the 16-ounce line specification looks like in a diagram.

LSL Nominal USL

15.90 16.00 16.10

The teams have asked that Charlie and Betty run 50 units on each of their four fill machines. The teams have asked to observe the setup, adjustment, operation, and measurement. Charlie is responsible for machines 1 and 2, and Betty is responsible for machines 3 and 4. We still have the de-mineralized and distilled water in the material distribution system. The results of the tests look like this.

Machine 1 Machine 2

25 25

20 20

15 15

10 10

05 05

00 00

15. 97 15.98 15.99 16.00 16.01 16.02 16.03 15.99 16.00 16.01 16.02 16.03

Freq: 1 5 8 18 14 3 1 8 24 14 3 1

Machine 3 Machine 4

25 25

20 20

15 15

10 10

05 05

00 00

15.97 15.98 15.99 16.00 16.01 16.02 16.03 16.04 16.05 15.97 15.98 15.99 16.00 16.01 16.02 16.03 16.04 16.05

Freq: 2 6 12 10 10 4 2 2 2 2 2 8 12 14 3 4 3 2

Assignment

  • For machine #1answer the following:

What is the mean? What is the range?

What is the standard deviation?

What is the lower process limit? The lower process limit is 3 standard deviations below the mean.

What is the upper process limit? The upper process limit is 3 standard deviations above the mean.

  • For machine #2 answer the following: What is the mean?

What is the range?

What is the standard deviation?

What is the lower process limit? The lower process limit is 3 standard deviations below the mean.

What is the upper process limit? The upper process limit is 3 standard deviations above the mean.

  • For machine #3 answer the following: What is the mean?

What is the range?

What is the standard deviation?

What is the lower process limit? The lower process limit is 3 standard deviations below the mean.

What is the upper process limit? The upper process limit is 3 standard deviations above the mean.

  • For machine #4 answer the following: What is the mean?

What is the range?

What is the standard deviation?

What is the lower process limit? The lower process limit is 3 standard deviations below the mean.

What is the upper process limit? The upper process limit is 3 standard deviations above the mean.

  • Which machine has the least variation?
  • Which machine is closest to the 16-ounce nominal value?
  • Which machine should we benchmark against?

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Input – Load – Pump – Release - Cycle

Operator

Material

In

Gating

Sensor

Method

Measurement

Line Pressure

Sensor

Fill Machine