DFSS: Module Quiz Flashcards
Which of the following is not an element in a Parameter diagram?
a. Input signals
b. Control factors
c. Noise factors
d. Performance attributes
Answer: Performance attributes
Explanation: Input signals, control factors, and noise factors are the elements in parameter diagrams. Performance attributes are a part of the Kano Model.
When does a company need to deploy Design For Six Sigma (DFSS)?
Answer: When there is no process in existence.
Explanation: DFSS is used in cases when either there is no process in existence or new processes are to be re-engineered. You would likely used DMAIC or Lean when processes need to be improved and controlled.
Which of the following parameters is not considered for assessment of reliability?
a. Improper usage by end users
b. Environmental factors
c. Defect cost
d. Stress strength
Answer: Defect cost
Explanation: The assessment of reliability usually involves testing and analysis of stress strength and environmental factors and should always include improper usage by the end user.
Which DMADV phase might make use of TRIZ?
a. Define
b. Measure
c. Design
d. Verify
Answer: Design
Explanation: TRIZ plays is important in the design phase. It is in this phase of creation, through breaking down barriers of novel thinking, that new products or processes that cannot be had with the current technologies, could be designed.
The primary benefit of Design for Maintainability is that is ______.
a. Increases the reliability
b. Less process variation
c. Minimizes the downtime
d. Reduction in testing time
Answer: Minimizes the downtime.
Explanation: Solutions developed using DFSS are often long life assets, meaning they could spend weeks, months, or even years in service. All systems require maintenance with time and use. With that in mind, maintainability is considered inherent to the system design, regarding the ease, accuracy, safety, and economy of maintenance tasks. The purpose of maintainability is to improve effectiveness and efficiency of maintenance. An effective DFM minimizes the downtime for maintenance while minimizing safety and error risks for operators.
Which of the following diagrams is used for preparation before completing the Design or Process FMEA in DFSS?
Answer: P-Diagram
Explanation: The Parameter Diagram (P-Diagram) is a block diagram which shows the connections between different parameters of a system. It is the ideal starting point for the FMEA.
What is the minimum expected process Sigma level for a DFSS product or service?
Answer: 4.5
Solution: DFSS is used to design or re-design a product or service from the group up. The expected process Sigma level for a DFSS product or service is at least 4.5 (no more than approximately 1 defect per thousand opportunities), but can be Sigma or higher depending the product.
Which of the following tools is used to estimate the effect of uncertainty on cost?
Answer: Monte Carlo simulation
Explanation: Monte Carlo simulation and other discrete-event simulation techniques are used to model uncertainty and to estimate the effect of uncertainty on cost.
In which phase of IDOV is a prototype created to ensure that the design meets the customer CTQs?
Answer: Validate
Explanation: In the Validate phase, a prototype or pilot build is created before the actual product launch to make sure that the design meets the customer CTQs. Whether the design is successful or not, the project documentation is completed and results are shared.
Genichi Taguchi proposed parameter design with the following two main objectives:
Answer: Average location of the response is at the desired level and variation of the response is as small as possible
Explanation: Parameter design proposed by Genichi Taguchi seeks a combination of controllable factors such that two main objectives are achieved:
- The mean or average location of the response is at the desired level
- The variation or dispersion of the response is as small as possible
Who introduced the parameter diagram concept?
Answer: Joseph Juran
Explanation: J.M. Juran explains the concept behind P-Diagrams in his book Quality Planning Analysis says “The most basic product feature is performance, i.e. the output.”
The Parameter diagram is part of the robust design approach. Robust parameter designs week to minimize the effects of the noise factors on quality. The Parameter Diagram (P-Diagram) is a block diagram which slows the connections between different parameters of a system. It is a great starting point for the Failure Models & Effects Analysis (FMEA), being useful when the item under analysis is a complex system containing many system interactions, operating conditions and design parameters, as it gives the team a clean way to see these elements visually.
DFX focuses on many internal and external objectives. Which of the following is centered on the internal category?
Answer: Design for testability
Explanation: If you think about where the requirements for each of the options come from, you can conclude that testability is the only internally driven category. Features, ergonomics, and appearance requirements should all come from end users or customers but testing requirements and practices must be developed internally to ensure the other requirements are met. Testing is a major part in the process to ensure that products have predetermined quality standards demands by the customers. In this stage the team must design steps that are required for validating the product to ensure that it does not have any defects and it is properly functioning.
Which of the following is required during the Design phase of IDOV?
Answer: Functional requirements
Explanation: The Design phase emphasizes CTQs and consists of identifying functional requirements, developing alternative concepts, evaluating alternatives, and selecting a best-fit concept, deploying CTQs and predicting sigma capability.
Which approach should be used when a process is available but not capable?
Answer: DMADV
Explanation: DMADV approach consists of Define, Measure, Analyze, Design, and Verify. According to this methodology, if a process does not exist, it has to be designed and verified.
This question asks about a process that exists but is NOT capable.
This goes back to the definition of capable. By capable we mean how much of the process could be expected to meet tolerance. If a process isn’t capable of achieving what it needs to achieve, no about of improving it will help.
This of it this way; if a manufacturing process is not performing as it should be, then you can work on improving the performance of the process using DMAIC.
Alternatively, if the manufacturing process used is not capable of producing output inside of the required tolerances, then the only solution is to examine the fundamentals of the process design.
Choose the correct statement:
a. DFMEA precedes PFMEA
b. Both DFMEA and PFMEA are simultaneous
c. PFMEA precedes DFMEA
d. Level of quality is set by PFMEA
Answer: a. DFMEA precedes PFMEA
Explanation: Design FMEA is usually completed before Process FMEA to make the design characteristics robust and achievable through the process.
