1. Explain what is QFD, (Quality Function Deployment)?

​

     The purpose of Quality Function Deployment approach is to bring the customer or person of interest to the design process. This method believes that by doing so, the continual improvement process gets more productive and efficient. If the customer gives their inputs on what they are looking for in a product or service, the company will have this information as a lead to their creation. This way the company can do a product that they know for a fact that the customer is looking for. This approach also applies to the inner company. It states that a functional QFD need the involvement of all the functional departments, this permits the design to have as many inputs as possible. QFD also promotes the use of benchmarking to make comparison between companies an also with customer satisfaction.

​

     2. Explain the WHATs in a QFD matrix

​

     The WHAT’s in a QFD matrix are considered as the customer requirements. It is basically what the customer wants to have in a product or service. The whole purpose of QFD is to have as much customer input as possible in order to create a successful product. For this reason, it is critical for the Quality Function Deployment Matrix to have this column or section completely designed to add the customer requirements. The ideal situation is to apply as much as possible.

​

     3. Explain the HOWs in a QFD matrix

​

     The HOW’s in a QFD Matrix is the other side of the WHAT’s table. The HOW’s are the technical descriptors or the product requirements needed to satisfy the customers’ requirements. This two sections are directly compared in the matrix to have a visual representation of what of the requirements the company is able to fulfill.  This is basically the part that the company studies their customer’s requirements and see how they can complete or grant the request.

​

     4. Explain the 1, or 3, or 9 interrelationship values in a QFD matrix

​

     This interrelationship values are the metric used to determine the strength of the link between the requirements with the HOW’s. In this metric, sometimes numbers are used; the greater the number, the greater the interrelationship.  “9” represents strongest relationship, “3” represents medium relationship, and “1” represents weak relationship.  In other cases, some companies use symbols instead, but with the same purpose. They decide the valor of each symbol and depending on the interrelationship is the symbol given to a particular requirement.

​

     5. Explain how you calculate the technical priorities in the design target matrix

​

     In order to determine de priority of a certain requirement, the team doing this research has to multiply the interrelationship ratings of the requirement, usually they are displayed by numbers (0, 1, 3 or 9) times the corresponding customer needs. At the end, the given number is multiplied by 100 to convert the number in a percentage. The information earned from this calculation is very valuable for them because with it they can decide how to distribute and allocate resources in a specific project to make it more efficient and cost-effective for them.

​

% Total priority = (Technical Requirement Priority, Ʃ Technical Priorities) * 100

​

     6. Define statistical process control

​

     It all started at Bell Laboratories thanks to Dr. Walter Shewhart. Japan was the first to adopt this method and with its help, they developed Total Quality. Statistical Process Control aims to maintain consistency in processes, making it easier to spot flaws and consecutively making improvements. The Statistical Process Control is successful because it lets you separate special cause variation from natural variation. This last one is the variation that can be improved more easily since it is constantly happening. In the other hand, special causes are extremely hard (if not impossible) to detect beforehand.  SPC uses predictions to help improve processes, eliminate waste and improve total quality. All of this can be done while reducing production costs since we are eliminating waste and other costs.

​

     7. Explain control charts for variables, with a simple mathematical example​

​

     A control chart for variables are structured as individual charts that all together are related displayed as a plot chart. This type of chart plots continuous measurement process data. Examples of these are length or pressure. All of this is measured in a time-ordered sequence. The shown image Is an example variable control chart which measures the number of new patients an institution has for each month. The limits are the minimum and maximum of patients expected to join. As we can see on the graph, all the dots are in the controlled area, meaning everything is running as planned.

​

​

​

​

​

 

 

 

 

 

 

 

 

 

 

 

 

 

     8. Explain control charts for attributes, with a simple mathematical example​

​

     Control charts for attributes may look like the same, but their metric is very different. This one is focused on things that can be counted, not measured. In the figure below, we can see a P Chart that indicates the portion of a specific product. Around 50 units are used for this chart and as we can see, only one of the items is out of control, passing the Upper Control Limit.

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

     9. Discuss and explain various continual quality improvement methods and tools

​

     Continuous quality is critical for any company that wants to keep up with the industry. A lot of companies have learned that quality is very important and maintaining yourself on top of it can lead to great economic advantages. Now a day, this term has become very famous and one of the main tools used is Six Sigma. This method seeks continuous improvements and its name comes from having six sigma errors per million, in other words, Six Sigma accepts 3.4 error for every million in total. Other methods or tools commonly used are Lean Manufacturing and TQM (Total Quality Management). All of this methods promote team work and involvement from all departments. They also strive to lower all waste, systemize all possible processes and reduce all variations.    

 

     10. Explain the way control charts could be used for quality improvements

​

     Control charts are a very useful tool that lets you know visually how the quality of your product or service is running. It is a fact that humans react better and faster to visual content than to written words. Control charts can be used for quality improvements because it is a great way of finding and correcting problems as they occur. Control charts lets you monitor your process constantly, giving you an accurate and fast way to determine if your process is stable. It lets you analyze patterns of process variations and separate them between special causes or common causes.

​

​