Understanding Total Quality Management - IV

Product Design

Product development is the process of creating a new product to be sold by a business or enterprise to its customers. A very broad concept, it is essentially the efficient and effective generation and development of ideas through a process that leads to new products.  Design refers to those activities involved in creating the styling, look and feel of the product, deciding on the product's mechanical architecture, selecting materials and processes, and engineering the various components necessary to make the product work. Development refers collectively to the entire process of identifying a market opportunity, creating a product to appeal to the identified market, and finally, testing, modifying and refining the product until it is ready for production. A product can be any item from a book, musical composition, or information service, to an engineered product such as a computer, hair dryer, or washing machine or a food. This document is focused on the process of inbreeding quality in to the products, rather than development aspects.

In a systematic approach, product designers conceptualize and evaluate ideas, turning them into tangible inventions and products. The product designer's role is to combine art, science, and technology to create new products that people can use. Their evolving role has been facilitated by digital tools that now allow designers to communicate, visualize, analyze and actually produce tangible ideas in a way that would have taken greater manpower in the past.

The task of developing outstanding new products is difficult, time-consuming, and costly. People who have never been involved in a development effort are astounded by the amount of time and money that goes into a new product. Great products are not simply designed, but instead they evolve over time through countless hours of research, analysis, design studies, engineering and prototyping efforts, and finally, testing, modifying, and re-testing until the design has been perfected.

Few products are developed by a single individual working alone. It is unlikely that one individual will have the necessary skills in marketing, industrial design, mechanical and electronic engineering, manufacturing processes and materials, tool making, packaging design, graphic art, and project management, just to name the primary areas of expertise. Development is normally done by a project team, and the team leader draws on talent in a variety of disciplines, often from both outside and inside the company. As a general rule, the cost of a development effort is a factor of the number of people involved and the time required to nurture the initial concept into a fully refined product. Rarely can a production ready product be developed in less than one year, and some projects can take three to five years to complete.

Product design is sometimes confused with (and certainly overlaps with) industrial design, and has recently become a broad term inclusive of service, software, and physical product design. Industrial design is concerned with bringing artistic form and usability, usually associated with craft design and ergonomics, together in order to mass-produce goods. Other aspects of product design include engineering design, particularly when matters of functionality or utility (e.g. problem-solving) are at issue, though such boundaries are not always clear.

Quality Function Deployment

A critical aspect of building quality into a product is to ensure that the product design meets customer expectations. This typically is not as easy as it seems. Customers often speak in everyday language. For example, a product can be described as “attractive,” “strong,” or “safe.” However, these terms can have very different meaning to different customers, because what one person considers to be strong, another may not necessarily accept. To produce a product that customers want, we need to translate customers’ everyday language into specific technical requirements. However, this can often be difficult. A useful tool for translating the voice of the customer into specific technical requirements is quality function deployment (QFD). Quality function deployment is also useful in enhancing communication between different functions, such as marketing, operations, and engineering.

QFD enables us to view the relationships among the variables involved in the design of a product, such as technical versus customer requirements. This can help us analyze the big picture — for example, by running tests to see how changes in certain technical requirements of the product affect customer requirements. An example is an automobile manufacturer evaluating how changes in materials affect customer safety requirements. This type of analysis can be very beneficial in developing a product design that meets customer needs, yet does not create unnecessary technical requirements for production.

QFD begins by identifying important customer requirements, which typically come from the marketing department. These requirements are numerically scored based on their importance and scores are translated into specific product characteristics. Evaluations are made of how the product compares with its main competitors relative to the identified characteristics. Finally, specific goals are set to address the identified problems. The resulting matrix looks like a picture of a house and is often called the house of quality.

Customer Requirements

Remember that our goal is to make a product that the customer wants. Therefore, the first thing we need to do is survey our customers to find out specifically what they would be looking for in a product. The importance customers attach to each of these requirements is also determined.

Competitive Evaluation

On the far right of our relationship matrix is an evaluation of how our product compares to those of competitors. For a example there are two competitors, A and B. The evaluation scale is from one to five —the higher the rating, the better. The important thing here is to identify which customer requirements we should pursue and how we fare relative to our competitors. This means that in designing the product, we could gain a competitive advantage by focusing our design efforts on a more appealing product.

Product Characteristics

Specific product characteristics are on top of the relationship matrix. These are technical measures.

The Relationship Matrix

The strength of the relationship between customer requirements and product characteristics is shown in the relationship matrix. A negative relationship means that as you increase the desirability of one variable; you decrease the desirability of the other. A positive relationship means that an increase in desirability of one variable is related to an increase in the desirability of another. This type of information is very important in coordinating the product design.

The Trade-off Matrix

The relationship matrix is beginning to look like a house. The complete house of quality is build based on above requirements. The next step in the building process is to put the “roof” on the house. This is done through a trade-off matrix, which decides how each product characteristic is related to the others and thus allows us to see what tradeoffs we need to make.

Setting Targets

The last step in constructing the house of quality is to evaluate competitors’ products relative to the specific product characteristics and to set targets for our own product. The bottom row of the house is the output of quality function deployment. These are specific, measurable product characteristics that have been formulated from general customer requirements.

The house of quality has been found to be very useful. It is very important see how it translates everyday terms like “lightweight,” “roominess,” and “nice looking,” into specific product characteristics that can be used in manufacturing the product. Note also how the house of quality can help in the communication between marketing, operations, and design engineering.

Reliability

An important dimension of product design is that the product functions as expected. This is called reliability. Reliability is the probability that a product, service, or part will perform as intended for a specified period of time under normal conditions. We are all familiar with product reliability in the form of product warranties. We also know that no product is guaranteed with 100 percent certainty to function properly. However, companies know that a high reliability is an important part of customer oriented quality and try to build this into their product design.

Reliability is a probability, likelihood, or a chance. For example, a product with 90 percent reliability has a 90 percent chance of functioning as intended. Another way to look at it is that the probability that the product will fail is 1 - .90 = .10, or 10 percent. This also means that 1 out of 10 products will not function as expected. The reliability of a product is a direct function of the reliability of its component parts. If all the parts in a product must work for the product to function, then the reliability of the system is computed as the product of the reliabilities of the individual components:

Rs = (R1) (R2) (R3) . . . (Rn)

Where Rs = reliability of the product or system.

R1... n = reliability of components 1 through n

Notice in the previous example that the reliability of the “system” is lower than that of individual components. The reason is that all the components in a series, as in the example, must function for the product to work. If only one component doesn’t work, the entire product doesn’t work. The more components a product has; the lower its reliability.

For example, a system with five components in series, each with a reliability of .90, has a reliability of only (.90)(.90)(.90)(.90)(.90) = (.90)5  = 0.59.

The failure of certain products can be very critical. One way to increase product reliability is to build redundancy into the product design in the form of backup parts. Consider the blackout during the summer of 2003, when most of the northeastern part of the United States was out of power for days. Critical facilities, such as hospitals, immediately switched to backup power generators that are available when the main systems fail. Consider other critical systems, such as the navigation system of an aircraft, systems that operate nuclear power plants, the space shuttle, or even the braking system of your car. What gives these systems such high reliability is the redundancy that is built into the product design and serves to increase reliability.

Redundancy is built into the system by placing components in parallel, so that when one component fails the other component takes over. In this case, the reliability of the system is computed by adding the reliability of the first component to the reliability of the second (backup) component, multiplied by the probability of needing the backup. The equation is as follows:

Notice that if the reliability of the 1st component is .90, the probability of needing a second component is equal to the first component failing, which is (1 - .90) = .10.

Process Management

According to TQM a quality product comes from a quality process. This means that quality should be built into the process. Quality at the source is the belief that it is far better to uncover the source of quality problems and correct it than to discard defective items after production. If the source of the problem is not corrected, the problem will continue. For example, if you are baking cookies you might find that some of the cookies are burned. Simply throwing away the burned cookies will not correct the problem. You will continue to have burned cookies and will lose money when you throw them away. It will be far more effective to see where the problem is and correct it. For example, the temperature setting may be too high; the pan may be curved, placing some cookies closer to the heating element; or the oven may not be distributing heat evenly.

Quality at the source exemplifies the difference between the old and new concepts of quality. The old concept focused on inspecting goods after they were produced or after a particular stage of production. If an inspection revealed defects, the defective products were either discarded or sent back for reworking. All this cost the company money, and these costs were passed on to the customer. The new concept of quality focuses on identifying quality problems at the source and correcting them.

Managing Supplier Quality

TQM extends the concept of quality to a company’s suppliers. Traditionally, companies tended to have numerous suppliers that engaged in competitive price bidding. When materials arrived, an inspection was performed to check their quality. TQM views this practice as contributing to poor quality and wasted time and cost. The philosophy of TQM extends the concept of quality to suppliers and ensures that they engage in the same quality practices. If suppliers meet preset quality standards, materials do not have to be inspected upon arrival. Today, many companies have a representative residing at their supplier’s location, thereby involving the supplier in every stage from product design to final production.

Summary

Today’s concept of quality, called total quality management (TQM), focuses on building quality into the process as opposed to simply inspecting for poor quality after production. TQM is customer driven and encompasses the entire company. Before you go on, you should know the four categories of quality costs. These are prevention and appraisal costs, which are costs that are incurred to prevent poor quality, and internal and external failure costs, which are costs that the company hopes to prevent. You should understand the evolution of TQM and the notable individuals who have shaped our knowledge of quality. Last, you should know the seven concepts of the TQM philosophy: customer focus, continuous improvement, employee empowerment, use of quality tools, product design, process management, and managing supplier quality.

Understanding Total Quality Management - III

Quality Tools

Continuous quality improvement process assumes and even demands that a team of experts in field as well as a company leadership actively use quality tools in their improvement activities and decision making process. Quality tools can be used in all phases of production process, from the beginning of product development up to product marketing and customer support. At the moment there are a significant number of quality assurance and quality management tools on disposal to quality experts and managers, so the selection of most appropriated one is not always an easy task. In the conducted research it is investigated possibilities of successful application of 7QC tools in several companies in power and process industry as well as government, tourism and health services. The seven quality tools are:

1. Cause and Effect Diagrams

2. Flow Charts

3. Checklists

4. Control Charts

5. Scatter Diagrams

6. Pareto Analysis

7. Histograms

 

You can see that TQM places a great deal of responsibility on all workers. If employees are to identify and correct quality problems, they need proper training. They need to understand how to assess quality by using a variety of quality control tools, how to interpret findings, and how to correct problems. In this section we look at seven different quality tools. These are often called the seven tools of quality control and they are easy to understand, yet extremely useful in identifying and analyzing quality problems. Sometimes workers use only one tool at a time, but often a combination of tools is most helpful.

Cause and Effect Diagrams

Cause and effect diagrams are charts that identify potential causes for particular quality problems. They are often called fishbone diagrams because they look like the bones of a fish. The “head” of the fish is the quality problem, such as damaged zippers on a garment or broken valves on a tire. The diagram is drawn so that the “spine” of the fish connects the “head” to the possible cause of the problem. These causes could be related to the machines, workers, measurement, suppliers, materials, and many other aspects of the production process. Each of these possible causes can then have smaller “bones” that address specific issues that relate to each cause. For example, a problem with machines could be due to a need for adjustment, old equipment or tooling problems. Similarly, a problem with workers could be related to lack of training, poor supervision, or fatigue. Cause and effect diagrams are problem solving tools commonly used by quality control teams. Specific causes of problems can be explored through brainstorming. The development of a cause and effect diagram requires the team to think through all the possible causes of poor quality.

Flow Charts

A flowchart is a schematic diagram of the sequence of steps involved in an operation or process. It provides a visual tool that is easy to use and understand. By seeing the steps involved in an operation or process, everyone develops a clear picture of how the operation works and where problems could arise.

Checklists

A checklist is a list of common defects and the number of observed occurrences of these defects. It is a simple yet effective fact finding tool that allows the worker to collect specific information regarding the defects observed. This means that the plant needs to focus on this specific problem; for example, by going to the source of supply or seeing whether the material is the issue; during a particular production process. A checklist can also be used to focus on other dimensions, such as location or time. For example, if a defect is being observed frequently, a checklist can be developed that measures the number of occurrences per shift, per machine, or per operator. In this fashion we can isolate the location of the particular defect and then focus on correcting the problem.

Control Charts

Control charts are a very important quality control tool. These charts are used to evaluate whether a process is operating within expectations relative to some measured value such as weight, width, or volume. For example, we could measure the weight of a sack of flour, the width of a tire, or the volume of a bottle of soft drink. When the production process is operating within expectations, we say that it is “in control.” To evaluate whether or not a process is in control, we regularly measure the variable of interest and plot it on a control chart. The chart has a line down the center representing the average value of the variable we are measuring. Above and below the center line are two lines, called the upper control limit (UCL) and the lower control limit (LCL). As long as the observed values fall within the upper and lower control limits, the process is in control and there is no problem with quality. When a measured observation falls outside of these limits, there is a problem.

Scatter Diagrams

Scatter diagrams are graphs that show how two variables are related to one another. They are particularly useful in detecting the amount of correlation, or the degree of linear relationship, between two variables. For example, increased production speed and number of defects could be correlated positively; as production speed increases, so does the number of defects. Two variables could also be correlated negatively, so that an increase in one of the variables is associated with a decrease in the other. For example, increased worker training might be associated with a decrease in the number of defects observed.

The greater the degrees of correlation, the more linear are the observations in the scatter diagram. On the other hand, the more scattered the observations in the diagram, the less correlation exists between the variables. Of course, other types of relationships can also be observed on a scatter diagram, such as an inverted U. This may be the case when one is observing the relationship between two variables such as oven be the case when one is observing the relationship between two variables such as oven temperature and number of defects, since temperatures below and above the ideal could lead to defects.

Pareto Analysis

Pareto analysis is a technique used to identify quality problems based on their degree of importance. The logic behind Pareto analysis is that only a few quality problems are important, whereas many others are not critical. The technique was named after Vilfredo Pareto, a nineteenth century Italian economist who determined that only a small percentage of people controlled most of the wealth. This concept has often been called the 80 – 20 rule and has been extended into many areas. In quality management the logic behind Pareto’s principle is that most quality problems are a result of only a few causes. The trick is to identify these causes.

One way to use Pareto analysis is to develop a chart that ranks the causes of poor quality in decreasing order based on the percentage of defects each has caused. For example, a tally can be made of the number of defects that result from different causes, such as operator error, defective parts, or inaccurate machine calibrations. Percentages of defects can be computed from the tally and placed in a chart. We generally tend to find that a few causes account for most of the defects.

Histograms

A histogram is a chart that shows the frequency distribution of observed values of a variable. We can see from the plot what type of distribution a particular variable displays, such as whether it has a normal distribution and whether the distribution is symmetrical.

In the food service industry the use of quality control tools is important in identifying quality problems. Grocery store chains must record and monitor the quality of incoming produce, such as tomatoes and lettuce. Quality tools can be used to evaluate the acceptability of product quality and to monitor product quality from individual suppliers. They can also be used to evaluate causes of quality problems, such as long transit time or poor refrigeration. Similarly, restaurants use quality control tools to evaluate and monitor the quality of delivered goods, such as meats, produce, or baked goods.