FMEA Part-3: DFMEA Application Case Studies

Summary

This video dives into two case studies on Design for Manufacturing and Assembly (DFMA) using Failure Mode and Effect Analysis (FMEA). It highlights the importance of evaluating potential failure modes in product design to ensure functionality, safety, and reliability. The first case study explores a pressure cooker, focusing on issues like steam leakage and safety valve malfunction. The second case study examines a lubricating oil pump, addressing risks like oil starvation and gear failure. Both case studies demonstrate how to prioritize improvements through systematic FMEA, ensuring effective design controls and risk mitigation in engineering processes.

Takeaways

• 😀 FMEA (Failure Mode and Effects Analysis) helps identify potential failure modes in designs to improve product safety and performance.
• 😀 The first case study focuses on a pressure cooker, where failure modes such as steam leakage and malfunctioning safety valves are analyzed.
• 😀 The pressure cooker FMEA prioritizes failure modes using Risk Priority Numbers (RPN) based on severity, occurrence, and detection rankings.
• 😀 The severity ranking for potential failures varies based on their impact on the function, with critical safety failures assigned the highest severity.
• 😀 The second case study deals with a lubricating oil gear pump, where failure modes such as low or no delivery and overloading are analyzed.
• 😀 In the lubricating oil pump case, failures are categorized as mission disabling, affecting the engine components and requiring careful monitoring.
• 😀 Design controls for preventing failures in both case studies include material specifications, tolerance checks, and regular testing (e.g., 500-hour test).
• 😀 The FMEA process includes a detailed action plan with responsible parties and deadlines to address identified risks.
• 😀 FMEA helps in prioritizing failure modes based on their RPN, allowing teams to focus on the most critical issues first.
• 😀 Both case studies emphasize the importance of detecting potential failures early in the design process to avoid costly post-production issues.
• 😀 The final goal of FMEA is to continuously improve product reliability and safety by implementing corrective actions and updating the analysis as needed.

Q & A

What is the primary function of a pressure cooker, as discussed in the FMEA case study?

The primary function of a pressure cooker is to cook food quickly while ensuring safety. It achieves this by releasing pressure if it exceeds a certain value to prevent accidents.

What does the FMEA table for the pressure cooker highlight as a potential failure mode?

The FMEA table for the pressure cooker highlights 'steam leakage' as a potential failure mode, which could cause cooking delays and result in burning or irritation.

How does aging rubber affect the design of the pressure cooker, according to the FMEA analysis?

Aging of the rubber ring in the pressure cooker can cause it to harden, reducing its ability to seal properly, which in turn increases the occurrence of steam leakage.

What was the severity ranking for the failure mode 'safety wall does not break at 1.3 kg/cm²' in the pressure cooker?

The severity ranking for the failure mode where the safety wall does not break at 1.3 kg/cm² was 10, as it poses a critical safety risk with potential for injury.

In the FMEA analysis of the lubricating oil pump, what is the main function of the pump?

The main function of the lubricating oil pump is to deliver oil at a specified pressure and flow rate, ensuring proper lubrication in the engine.

What is the consequence of low delivery or no delivery in a lubricating oil pump?

Low or no delivery of oil from the pump can lead to oil starvation, potentially causing failure of critical engine components like bearings, pistons, and camshafts.

Why was the severity ranking for oil starvation in the lubricating oil pump set at 8?

The severity ranking was set at 8 because oil starvation leads to mission-disabling engine failure, although it may not violate safety or regulatory standards.

What is the purpose of conducting a Fujifilm test in the FMEA of the lubricating oil pump?

The Fujifilm test is used to check the sealing quality of the gasket in the lubricating oil pump, ensuring that leaks do not occur due to inadequate gasket sealing.

What actions were recommended for improving gasket sealing in the lubricating oil pump FMEA?

The recommended actions included conducting a design of experiments (DOE) for low and high flatness, testing gasket material, and performing additional tests on worst-case gasket scenarios.

How does the occurrence ranking in the FMEA influence the prioritization of actions?

The occurrence ranking helps determine the likelihood of a failure mode happening, which, combined with severity and detection rankings, drives the prioritization of corrective actions.