Production and Operation in Manufacturing

Quality
Customers that are businesses will define quality very clearly using specifications, standards, and other measures. This makes the point that quality can be defined and measured. Although few consumers

could define quality if asked, all know it when they see it. This makes the critical point that quality is in the eye of the beholder. With the total quality approach, customers ultimately define quality. (Derek L. Waller. 2002)

People deal with the issue of quality continually in their daily lives. We concern ourselves with quality when grocery shopping, eating in a restaurant, and making a major purchase such as an automobile, a television, or a personal computer. Perceived quality is a major factor by which people make distinctions in the marketplace. Whether we articulate them openly or keep them in the back of our minds, we all apply a number of criteria when making a purchase. The extent to which a purchase meets these criteria determines its quality in our eyes.

One way to understand quality as a consumer-driven concept is to consider the example of eating at a restaurant. Most people apply such criteria as the following:
? Taste
? Response time
? Food preparation
? Service
? Environment
? Price
? Selection

Personally the way driven me to choose the restaurant is the taste, other factors will be the environment, food preparation and service. Because we go to the restaurant for lunch or dinner, want to have a nice time and happy mood with it. I think taste is the most important factor, if the taste is wonderful customers will continue visit this restaurant even introduce their friends to come. Otherwise they will lose their customers. On the other hand, the environment, response time, food preparation, price and selection all are also very important for a restaurant. A good restaurant is good for everything, the food is fresh and won’t let customers wait so long for their food. And their staff service also very good, for example the customer don’t have enough drink in their cup then the staff will top up their cup. Another example is the customer order something not sell in this restaurant but the customer don’t know, the staff worker still go somewhere and buy the thing order by the customer. Try their best to satisfy the customers demand then I can make sure the customer will visit the restaurant again, because customer happy with the restaurant, happy with the staff and happy with the service of this restaurant.

Quality Management
Quality management is a method for ensuring that all the activities necessary to design, develop and implement a product or service are effective and efficient with respect to the system and its performance. (www.wikipedia.com)

Quality Standards
The International Organization for Standardization (ISO) created the Quality Management System (QMS) standards in 1987. These were the ISO 9000: 1987 series of standards comprising ISO 9001: 1987, ISO 9002: 1987 and ISO 9003: 1987; which were applicable in different types of industries, based on the type of activity: designing, production or service delivery. The standards have been regularly reviewed every few years by the International Organization for Standardization. The version in 1994 and was called the ISO 9000: 1994 series; comprising of the ISO 9001: 1994, 9002: 1994 and 9003: 1994 versions. The last revision was in the year 2000 and the series was call ISO 9000: 2000 series. However the ISO 9002 and 9003 standards were integrated and one single certifiable standard was created under ISO 9001: 2000. Since December 2003, ISO 9002 and 9003 standards are not valid, and the organizations previously holding these standards need to do a transition from the old to the new standards. The ISO 9004: 2000 document gives guidelines for performance improvement over and above the basic standard.

The Quality Management System standards created by ISO are meant to certify the processes and the system of an organization and not the product or service itself. ISO 9000 standards do not certify the quality of the product or service.

Recently the International Organization released a new standard, ISO 2000, meant for the food industry. This standard covers the values and principles of ISO 9000 and the HACCP standards. It gives one single integrated standard for the food industry and is expected to become more popular in the coming years in such industry. The most elaborated and accepted concept of quality management is the model of the EFQM Excellence Model. (www.wikipedia.com)

Now I’m gonna introduce a Dumpling Restaurant called Ding Tai Feng, this company got their own restaurant and service. They produce the dumpling by them-self and provide service by them-self as well. No matter how good the Ding Tai Feng’s manager manage his restaurant, but they still got some problems can not avoid. Such problems from two ways: one way is manufacturing environment, other way is service environment.

For this dumpling restaurant which name is Ding Tai Feng I’ll use the following five quality tools to describe the problems that Ding Tai Feng face. For Manufacturing Environment I’ll use:
? Pareto Chart
? Histogram
? Check Sheet
For Service Environment I’ll use:
? Scatter Diagram
? Run Chart

Pareto analysis
A Pareto analysis, named after Vilfredo Pareto a 19th-century Italian economist, is a graphical representation showing the frequency of the causes of a problem. (Operations Management) people use pareto charts can help them to focus attention on those categories of variables that occur most frequently, and to weight the factors being considered to enable priorities for action on those items that most need attention.

Manufacturing
This is shown in Figure 1. Dumpling meat filling is the major problem, which may be directly related to customers.

Reasons for People don’t like the dumpling Number of Customers Percentage %
Meat Filling 57 51.82
Vegetable 22 20.00
Dough 18 16.36
Source 9 8.18
Soup 4 3.64
Total 110

Figure 1
From Figure 1 which quality tool named Pareto Chart we can see the Meat Filling is the biggest problem that people don’t like the dumpling from Ding Tai Feng which the percentage is 51.82. So Ding Tai Feng has to pay attention on this area and ask for the reason why the customers don’t like the meat filling and improve it. Otherwise this dumpling restaurant will shut down soon. From this chart we can see all the factors very clearly and easy to pay attention on the most important factors. Meat filling is the biggest problem, other factors are vegetable, dough, source and soup and the percentage for them are 20%, 16.36%, 8.18% and 3.64%.

Histogram
In statistics, a histogram is a graphical display of tabulated frequencies. A histogram is the graphical version of a table that shows what proportion of cases fall into each of several or many specified categories. The histogram differs from a bar chart in that it is the area of the bar that denotes the value, not the height, a crucial distinction when the categories are not uniform width. The categories are usually specified as non-overlapping intervals of some variable. The categories must be adjacent. (www.wikipedia.com)

Understanding a few basic facts is fundamental to the use of statistical techniques for quality and process applications. All processes are subject to variability, or variation by histogram. There are many examples of this. But I want to use the graph about the Ding Tai Feng selling the dumpling in different weight range of meat filling. Under the Ding Tai Feng’s manager don’t know the market before so he tests the market start by 21~30g weight meat filling inside the dumping so they found they sold 10 dumplings per day. After the first step they continue test the market and each time add 10 more G than last test. Every time they add more meat filling inside of the dumpling and the dumpling they sold were more and more than last time. Till the weight of meat filling is 41~50g they sold 98 dumplings per day. On the other hand this is the best selling till now. After this range which is 41~50g the selling will be drawn. Then Ding Tai Feng’s manager will know the weight of meat filling around 41~50g was the best selling of dumplings. So they will consider this range of weight and produce the dumpling that can make the Max profit.

From the graph Figure 2 we also can see very clearly when the range is 41~50 the podetium is the highest one. When this restaurant start test the market from the first day is the lowest just put 21~30 meat filling so the customers don’t like it then the selling number of the dumpling is less.

The flatter and wider the frequency distribution curve, the greater the process variability. The taller and narrower the curve, the less the process variability. Even though the variability may change from process to process, it would be helpful to have a common means of measuring, discussing, or understanding variability. Fortunately Ding Tai Feng do.

To express the process’s variability we need to know only two things, both of which can be derived from the process’s own distribution data: standard deviation and mean. Standard deviation is represented by the lowercase Greek letter sigma (?) and indicates a deviation from the average, or mean, value of the dumplings in the data set. The mean is represented by the Greek letter mu (?). In a normal histogram, ? is seen as a vertical line from the peak of the bell curve to the base, and it is the ling from which deviation is measured, minus to the left of ? and plus to the right. Standard deviation (?) is normally plotted at -2?,-1? (left of ?), and +1?, +2? to the right (refer to Figure 3). Because mean and standard deviation are always derived from data from the process in question, standard deviation has a constant meaning from process to process.

Check Sheet
The check sheet is a simple document that is used for collecting data in real-time and at the location where the data is generated. The document is typically a black form that is designed for the quick, easy, and efficient recording of the desired information, which can be either quantitative or qualitative. When the information is quantitative, the check sheet is sometimes called a tally sheet.

A defining characteristic of a check sheet is that data is recorded by making marks on it. A typical check sheet is divided into regions, and marks made in different regions have different significance. Data is read by observing the location and number of marks on the sheet. (www.wikipedia.com)

Figure 4

From figure 4 we can easy to see the problem of Ding Tai Feng got. Depend on the customer’s feedback about the dumpling from Monday to Sunday. Everyday got the same problem and same feedback but the times are different. Meat filling smelly, vegetable not fresh, dough too thick source too sweet and worm inside soup are the major problem feedback made by customers. We can see on Monday they got a lot of problem especially the meat filling smelly and dough too thick, maybe the stuff are lazy to work or something like that. But on Friday they got fewer problems, seem like near the weekend all people working very hard.

Scatter Diagram
The scatter diagram is used to determine the correlation between two characteristic. Suppose you have an idea that there is a relationship between dumpling sold and the percentage of delivery per day. Percentage of delivery per day on the y-axis and number of dumpling sold per day on the x-axis; percentage of delivery per day and number of dumpling sold per day are the two characteristics.

Examination of the scatter diagram of Figure 5 shows that the aggregate of data points contains a slope up and to the right. This is correlation, and it supports the thesis that many people like to eat the Ding Tai Feng’s dumpling. But they all lazy to go out so would like use to use the phone call and order the dumpling which is delivery. But figure 5 is a collection of scatter diagrams illustrating strong positive collection.

Figure 5
Run Chart
A run chart is a graph that displays observed data in a time sequence. Often, the data displayed represent some aspect of the out put or performance of a manufacturing or other business process. (www.wikipedia.com)

For example this run chart is talking about the quantity demand of dumpling from Monday to Sunday. Time is generally represented on the horizontal (x) axis and the property under observation on the vertical (y) axis. Often, some measure of central tendency of the data is indicated by a horizontal reference line. We can see very clearly from Monday to Thursday the curve is going up day by day. On the other hand is the quantity demand of dumpling is getting higher. Seem from Friday to Saturday the line is dropping down maybe the customers want to change the food to eat. After Saturday the curve going up again. We use run chart can help us easy to get information about the quantity demand of customers and the Ding Tai Feng’s manager can produce the dumpling to satisfy the customers.

In conclusion I was done the five quality tools in Ding Tai Feng the manufacturing dumpling which are: Pareto Chart, Histogram and Check Sheet for manufacturing environment. Scatter Diagram and Run Chart for service environment. The company use these five quality tools can see the problems easier; can help them find the way to fix the problem faster.

References:

? David L. Goetsch & Stanley B. Davis. (2006). Quality Management, Upper Saddke River, New Jersey 07458.
? Derek L. Waller. (2002). Operations Management, Second Edition, USA: Thomson
? http://en.wikipedia.org/wiki/Quality_management
? http://en.wikipedia.org/wiki/Histogram
? http://en.wikipedia.org/wiki/Check_sheet
? http://en.wikipedia.org/wiki/Run_chart

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