Hazard Analysis in Product Engineering & Design
Product safety is paramount in today’s design and engineering landscape. With regulatory requirements constantly evolving, designers are more accountable than ever to ensure products are safe, reliable and robust against misuse.
This responsibility is managed through Hazards Analysis, a structured approach to identifying and mitigating potential risks in a product’s lifecycle. Hazards Analysis isn’t just about preventing failure; it’s about proactively designing for safety under a range of foreseeable scenarios.
What is Hazard Analysis?
At its core, Hazard Analysis assesses the risks associated with product failure or misuse, addressing various circumstances—environmental conditions, manufacturing anomalies, age-related fatigue and stress. Product designers use Hazards Analysis to pinpoint possible issues at early stages, integrating safer design choices from the outset. Hazards Analysis considers all aspects of product use, including:
Intended Use: How the product is meant to function under normal conditions.
Unintended Use: Unpredictable or improper usage that could still realistically happen.
In addition to creating safer designs, Hazards Analysis provides a framework for meeting compliance standards in highly regulated fields, such as healthcare, aerospace and consumer electronics.
Essential Tools in Hazards Analysis
Two primary tools underpin effective Hazards Analysis:
- Failure Mode Effects Analysis (FMEA)
- Misuse Mode Effects Analysis (MMEA)
These methods provide a systematic way to identify, assess and mitigate hazards, ensuring that each aspect of the design is rigorously tested and reviewed.
Understanding Failure Mode Effects Analysis (FMEA)
What is FMEA?
FMEA focuses on identifying potential failure points within a product’s design and analysing the consequences of these failures. By considering all potential single-point failures, designers can evaluate and classify risks to guide design improvements.
How FMEA Works
The process of FMEA involves defining what constitutes a “failure” and then assessing the impact of that failure on the product’s functionality and the user. A “failure” is defined as the loss of a critical function under a given condition—essentially, any scenario in which the product or one of its components stops working as intended. Through FMEA, product teams evaluate the severity and probability of each potential failure.
Risk Assessment Using Severity & Probability
FMEA relies on a matrix that classifies risk based on severity and probability:
Severity Levels
- Major: Potential for severe injury or death
- Moderate: Injury requiring medical attention
- Minor: Non-serious injuries with no medical intervention
- Negligible: No risk of injury or harm
Probability Categories
- Frequent: Likely to occur multiple times throughout the product’s life
- Probable: Expected to happen at least once during the product’s use
- Occasional: Might occur once in a while
- Remote: Rare but possible
- Improbable: Highly unlikely during the product’s life
By evaluating a failure’s severity and likelihood, designers assign a Risk Priority to each potential issue, classifying it as:
- Unacceptable: Must be mitigated before production
- Acceptable: Meets design standards with no further action required
- As Low as Reasonably Practical (ALARP): Mitigation isn’t necessary, but risks are noted
ALARP represents cases where failure, if it occurs, does not result in injury, though the likelihood of occurrence is low. This classification allows for balanced decisions on whether further design modifications are needed.
Real-World Example: The Coffee Cup
Imagine a simple coffee cup. The handle is a potential single-point failure. If it breaks, boiling liquid could spill, posing a serious burn risk. Even if the probability of this occurring is low, the severity is high, making the risk unacceptable. Designers might then select a stronger material, adjust the handle design, or improve quality control to reduce the likelihood of failure.
Misuse Mode Effects Analysis (MMEA)
What is MMEA?
MMEA is like FMEA but specifically addresses situations of improper use. MMEA considers scenarios where users may unintentionally or intentionally misuse the product, whether due to frustration, carelessness, or misunderstanding of the product’s purpose.
Why MMEA is Important
Even if a product functions flawlessly when used as intended, there are often situations in which users may misuse it. This tool is essential for products where misuse could still result in harm. By addressing such risks, MMEA helps ensure safety beyond conventional use cases.
Applying MMEA: Revisiting the Coffee Cup
Continuing with the coffee cup example, MMEA would evaluate scenarios like slamming the cup down in frustration. While most coffee cups aren’t designed for such impact, the severity of a handle breaking due to rough handling might be moderate and the probability remote. Still, it may lead to design adjustments, such as including fair usage instructions or testing for durability under slight stress conditions.
Key Steps in Conducting Hazards Analysis
Hazards Analysis is a collaborative process that involves:
- Identifying Potential Hazards
Assess risks in the product’s intended environment and under realistic misuse cases
- Evaluating Severity and Probability
Use FMEA and MMEA matrices to classify and prioritise risks based on potential impact and frequency.
- Mitigating Risks
For unacceptable risks, alter the design, choose safer materials, or add fail-safes.
- Reviewing and Approving Designs
After identifying and mitigating hazards, the product undergoes multiple layers of review by technical, management and regulatory teams.
- Documentation and Compliance
Hazards analysis isn’t just about design; it’s also about documentation to demonstrate compliance with industry regulations. This step is essential for highly regulated fields like medical devices or consumer electronics.
- Continual Improvement
Hazards analysis is not static. Products may face new risks over time, especially if used in unforeseen ways. Periodic reviews and updates to the analysis are recommended.
Mitigating Risks: Practical Approaches
For development teams, addressing unacceptable risks is crucial before final production. Risk mitigation can take many forms, including:
- Altering the design to remove or reduce the likelihood of failure.
- Using stronger, more durable materials.
- Providing clear usage guidelines to minimise misuse risks.
- Implementing more rigorous quality control checks during manufacturing.
Hazard analysis remains an indispensable part of product engineering. It not only protects users but also safeguards businesses from liability issues and compliance failures. By understanding and mitigating potential hazards, designers help ensure that products are as safe and reliable as possible in an increasingly complex and regulated world.
Hazards analysis is more than a design tool—it’s a responsibility. In today’s marketplace, it’s an essential part of creating products that meet both regulatory and consumer expectations for safety and quality.
