Using Quantitative Methods to Manage Quality at a Chinese Assembly Facility

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Company Background

Mr. Qiang is the owner of Fuxing Caster Company Ltd. located in Yantai, China. His company has been in operation since 2010. Fuxing produces vibration-dampening, machine balancing mounts. Customers use mounts to balance and isolate sensitive equipment from floor vibrations.
Last year the company sold 30,000 mounts generating approximately 2.5 million RMB is sales . Nearly all sales were to Chinese original equipment manufacturers (OEMs). While the domestic market is very large, intense price competition has resulted in tight margins. To boost profitability, the company has started selling mounts overseas. The company has an English language website (Figure 1) and contracted with an international distributor. The distributor presently has 15,000 Fuxing mounts in inventory.

 

Problem

The distributor is pleased with the 85 RMB price for mounts and on time delivery. Unfortunately, a few customers have had issues. The problem is wheel swivel. Wheels need to freely swivel, otherwise, it’s difficult to position machine tools prior to balancing. The distributor doubts that 99% of mounts in his inventory, as promised in the purchase order, are of good quality.
The quality engineer at Fuxing suspects that the problem can be traced back to bearing assembly. Too little lubrication could cause mounts to bind. Too much preload on the bearing could cause the same issue. Next week the distributor has scheduled a meeting with Mr. Qiang to discuss wheel swivel. Key questions he expects answers to are, “What percentage of his inventory is potentially defective?” and “What process changes will be implemented to ensure no more than 1% of mounts are nonconforming?”
Assembly Operation

At Fuxing mounts are assembled on a single production line which operates one shift per day four days per week. One day per week is spent making packages and labels. Three associates work full time on the line. New hires are paid 2 RMB/hr. base pay. Each associate is scheduled to work one, seven hour shift per day. Planned downtime includes a 30 minute break for lunch and two, fifteen minute rest breaks per day. After accounting for plant shut downs, Chinese New Year and national holidays, the plant operates 5 days per week 39 weeks per year.
One mount is assembled on the line every two minutes after taking into account set ups, material handling, scrap, rework and unplanned downtime. Of the five steps involved in making a mount, bearing assembly (as shown in Figure 2) is easily the most time consuming. It involves lubricating each angular contact ball and torque wrench tightening a preload nut to seat the bearing.

Figure 2: Bearing assembly

To distribute the work load evenly, each of the three operators alternate by week time spent on the line assembling bearings. The quality engineer was able to collect 15 batches of mounts traceable back to which operators performed assembly. She was also able to collect a few defective mounts from the distributor. All of these parts were sent to an outside lab for measurement of swivel torque. The lab determined mount quality is binary. They are either good or bad based up swivel torque. For example, if swivel torque, at 95% confidence, exceeded the desired amount by 15 N-cm mounts were bad. Otherwise, mounts were good. Based on this N-cm limit, the average amount of defective mounts by assembly worker across batches are listed in Table 1.

 

 

 

 

Table 1: Percentage Defective Mounts
Sample Group Operator 1 Operator 2 Operator 3
1 0.37% 0.50% 0.33%
2 0.70% 0.33% 0.33%
3 0.33% 0.43% 0.17%
4 0.50% 0.67% 0.20%
5 1.10% 0.70% 0.33%
6 0.70% 0.40% 0.63%
7 0.73% 0.33% 0.63%
8 0.53% 0.50% 0.67%
9 0.63% 0.67% 0.34%
10 0.70% 0.70% 0.37%
11 0.40% 0.20% 0.25%
12 0.60% 0.50% 0.20%
13 0.70% 0.63% 0.40%
14 0.87% 0.43% 0.33%
15 0.43% 0.40% 0.23%

Upon reviewing this data, the operations manager noted the only difference among the three assembly line workers was their experience. Operator #1 has worked at the factory for less than a year. Operator #2 has 2 years’ experience. Operator #3 has nearly 3 years’ experience. The HR manager explained that Operator #3 would be leaving next month. Her labor contract was expiring.
Per Chinese Labor Law all full time employees work under contracts. The employer has the option of offering 1, 2 or 3-year contracts. Part time workers are not required to have contracts, but they can work no more than 20 hours per week. At Fuxing assembly line workers are offered 3-year contracts. To keep them from quitting over the course of their contracts management provides five percent pay increases per year along with annual bonuses equal to two months’ salary. To control the rise in labor costs Mr. Qiang has been considering use of 2 year contracts.
In addition to operator impact the quality engineer and operations manager also considered other solutions to the caster wheel swivel problem. On the one hand, if bearing lubrication and bearing preload could be controlled within 0.1 grams and 0.1 N-cm respectively perhaps swivel torque could be controlled without actually measuring it. To test this hypothesis the quality engineer recorded lubrication amounts and bearing preload settings for 14 mounts. Mounts were then sent out for swivel torque measurement. Results are summarized in Table 2.
Table 2: Swivel Torque by Lubrication and Preload Setting
Assembly Grease (grams) Preload (N-cm) Measured Torque (N-cm)
1 1 20 20
2 1.1 21 22
3 1.2 20.9 20.8
4 1.3 20.2 20.3
5 1.5 20.9 20.9
6 1 21 21
7 0.9 22 22
8 0.9 22.3 22.3
9 0.8 23 23
10 1 23.3 22
11 1.3 22 22
12 1.5 22.4 22.3
13 1 22 21
14 1 22 22

Another option the quality engineer and operations manager discussed is spending 600,000 RMB on a machine capable of directly measuring swivel torque. The machine requires 2.2 minutes to load a part, calibrate, conduct measurement and unload. The machine is 91% efficient after taking into account planned and unplanned downtime. Given the high machine price Mr. Qiang would only consider purchasing a single unit. Fuxing produces all its products to a single quality standard. That said, Mr. Qiang would only approve machine purchase if it’s capable of ensuring at 99% probability all 30,000 mounts made per year are good. A proponent of The Fallacy of 100% Inspection (Gunter, 1983), Mr. Qiang is adamant that he will not approve making mounts for inventory to be sorted at a later time. He is, however, agreeable to hiring a full time or part time inspector at 2 RMB/hr. to operate a measurement machine so long as the inspector is at least 60% utilized. In light of these constraints the quality engineer met with the operations manager and HR manager to put together a plan.

Discussion Questions

1. At 95% probability how many defective mounts are in inventory at the distributor?
2. At 95% probability what is the potential replacement cost of these mounts?
3. What is the recommended process at Fuxing to ensure no more than 1% of mounts are nonconforming?
4. At 95% confidence what is the potential scrap and labor cost of implementing your new process?

References

Gunter, B. (1983). The Fallacy of 100% Percent Inspection. ASQ Statistics Division, Newsletter 5,1. Retrieved from: http://asq.org/statistics/2011/11/quality-control/the-fallacy-of-100-inspection.pdf

 

 

Sample Solution

 

2100: Bed time for family. Adolescents shower, go to their rooms to do schoolwork, and hit the sack.

Field Analysis: Benjaminson’s Life

When we conscious every day, we start with a run of the mill schedule. All that we do in life every day is planned and on a calendar. Work begins at a specific time, school begins at a specific time, childcare, etc. Individuals are should have been at these spots now and again that help other individuals live their lives and can begin about their day as they typically do. We as a whole have a job we play throughout everyday life and in our family. Social standards are the desire for our jobs in the public eye and how they play out paying little respect to race, sexual orientation, and ethnicity. We as individuals adjust to what our social job is, and our practices adjust to what is anticipated from us. I am a mother and a spouse, those are my jobs. I have three offspring of every extraordinary age. They all anticipate that me should get things done for them consistently. I have fit in with these assignments and preform them day by day. Without my doing my part and assuming my job, my family’s lives would be changed. Having a social structure in life is having a customary reliable timetable. Social structure offers security to families and keeps a reliable and normal stream to life. Family is the most significant and most powerful operator in the socialization of individuals in the public arena (Howard and Showel, 1953).

I accept that in the public eye, everything needs to cooperate so as to work appropriately. Functionalism is required in the public eye. For instance, I need to keep in steady correspondence with my significant other so as to ensure we are monetarily steady, our kids are appropriately thought about, and we can achieve errands for ourselves and the family. In an article I was perusing on the web, it states how functionalism is critical to society as it takes a gander at how everybody in the public eye has a job they play to make the world capacity to some degree regularly and keeps it adjusted (Henry, 2016). With the end goal for society to work all in all, everybody and everything needs to cooperate and bode well. With the end goal for society to work similarly and the most steady, every individual has a job throughout everyday life, and that job adds to making society work all in all (Mooney et al, 2007). My youngsters recognize what time they have to wake up and what time they have to go out to make it to class on schedule. My most established girl works low maintenance work notwithstanding her secondary school and school classes. She realizes she should do well so as to graduate and have the option to set off for college. She realizes she should be grinding away on time so as to not get in a difficult situation and be terminated.

Ordinary every individual in my family awakens and has their own example of undertakings. Every single one of my relatives assumes a significant job in the public arena. My youngsters go to class, so they contribute as understudies in the instruction framework. They are bettering themselves with getting training so they can proceed onward to school. My youngsters have grown up realizing that having a secondary school certificate is significant in having openings for work as they are more established. They comprehend that credentialism has an impact in their prospects. My significant other gets down to business consistently. The job he plays in the public arena is significant in that he can keep a few hoodlums off the boulevards and issue references to individuals who are overstepping the law and submitting a type of aberrance. I presently work low maintenance in the wake of working all day for as far back as 20 years in the military. My job has altogether changed, as now my better half is the essential supplier for our family. I am presently ready to play more into conventional sexual orientation jobs as the homemaker, who is answerable for keeping the house spotless, dealing with the youngsters, and doing the shopping for food.

Since I don’t work all day hours, I have more opportunity to take a shot at myself. I have more opportunity to concentrate on my school courses, and more opportunity to go to the rec center. Having more opportunity to concentrate on my school classes makes me a superior individual, and gives personal time to comprehend and peruse the material all the more altogether. I am presently ready to be a progressively steady understudy, partake in the gathering dialogs, and work on my papers for my classes. Being an undergrad isn’t simple, over being a mother, and furthermore holding low maintenance work. I am as yet liable for signing into my PC and finishing on the web undertakings. Having the option to go to the rec center all the more regularly, and go for a run causes me rationally and physically. I am less worried and ready to concentration and connect with individuals who are doing likewise things I am. With having the option to go to the rec center all the more regularly, I am ready to mingle more with individuals at the exercise center. Having these social collaborations at the rec center, help me figure out how to practice appropriately, help in structure dependable connections, and help me mingle more. Social structure outlines these social connections, and the significance of having them in our everyday lives.

Changing from a full-time military part, to low maintenance working, for the most part homemaker, has been an extremely hard progress. Going from a position where my job was a senior chief, giving more than 12 hours per day physically and being available to come back to work for 24 hours for my colleagues and guaranteeing their security and prosperity were need, and that we were prepared to take on any undertaking whenever, to a job where I can concentrate more on myself and my family was not a simple job change. Society would believe that this change would be a simple one, and take no time by any stretch of the imagination. In the military I was a pioneer, a guide, a tutor to many individuals. I have affected individuals in positive manners with my insight and ability. Realizing I have helped other people and tutored them emphatically, makes me feel like I have added to society and I am a piece of what makes society work in general. The military has given me a ton of preparing in administration, and setting a positive model for other people. The military has even given me preparing on the best way to progress all the more effectively. It demonstrates that our jobs in the public eye can change so immediately, regardless of whether we aren’t prepared for our job to change. We need to figure out how to adjust to our new job and fit in with it.

Perceiving how all these sociological ideas have a tremendous impact in a people day by day life truly make me perceive how significant each and everybody is in the public eye. Our jobs, our every day schedules, our day by day lifestyles truly are significant and are required for society to work. We come into a job as we develop into society. In an article about human science I was perusing, it expressed that we are results of our condition. That individuals like to think they settle on their own decisions by their very own impulses and responses, however they are settling on these choices dependent on what society has impacted them to do (Kaufman, 2018). I accept this to be valid. Individuals are exceptionally affected by what they see and how they see others affecting society.

Everybody has a schedule each day, and we as a whole figure out how to adjust to that. Knowing our job in the public arena and how it fits in and functions is significant. The job I take is the run of the mill female sexual orientation job of a mother, a spouse, and homemaker My job alone establishes the pace for social structure in my family. My family has become used to my job and my duties. Socialization inside a family is significant. Family is imperative to me and is my primary need to guarantee they are very much dealt with and are accepting the best open doors society brings to the table them. I am extremely grateful for every one of the open doors I have had in life up until now, and just anticipate the following difficulties I will be looked with in the public arena.

References

Crossman (2018). Understanding Functionalist Theory. Recovered from https://www.thoughtco.com/functionalist-viewpoint 3026625

 

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