The key difference between FMEA and DFMEA is that FMEA is used for products, processes and services in organizations whereas DFMEA is used only for designs of products.
There are two types of FMEA (Failure Mode Effects Analysis): DFMEA and PFMEA. DFMEA stands for Design Failure Mode Effects Analysis while PFMEA stands for Process Failure Mode Effects Analysis. Moreover, FMEA is a common methodology we can observe in the manufacturing and engineering sectors; they reduce the potential failure of their systems as well as operating and design costs.
CONTENTS
1. Overview and Key Difference
2. What is FMEA
3. What is DFMEA
4. Relationship Between FMEA and DFMEA
5. Side by Side Comparison – FMEA vs DFMEA in Tabular Form
6. Summary
What is FMEA?
FMEA stands for Failure Mode Effects Analysis. FMEA is a step-wise approach to identify all possible failures in a design, failures in operations or assembly processes, or a product or service. The methodology of FMEA categorizes all failures based on the likelihood and severity of the failure. “Failure mode” refers to any defects or errors in design, process, or item, which affect the customer. Meanwhile, effects analysis refers to the study of the consequences of the failures.
Furthermore, FMEA documents existing knowledge and actions related to risks of failures and use them for continual improvement. FMEA usually begins at the earliest theoretical stages of design and continues throughout the life span of the product or service.
Moreover, FMEA is a proactive approach that identifies potential causes prior so that major lapses can be corrected accordingly to avoid major lapses. This application is widely used in the manufacturing sector.
FMEA is used in the following situations:
1. Before launching a new process, product, or service.
2. When using an existing process, product, or service in a new way
3. Before developing control plans for a new or altered process
4. As a continual improvement for the existing process
5. When repetitive complaints or failures are reported in the existing product, process or service
6. Timely review throughout the life of the process, product, or service
What is DFMEA?
DFMEA stands for Design Failure Mode Effects Analysis. This methodology can identify potential failures in product designs at the development stage. In fact, DFMEA was first used in rocket science to prevent failures. Today, many industries use this methodology to identify risks, take countermeasures and prevent failures. In most instance, engineers use this as a procedure to explore the possibility of design failure in a real-world situation.
First, DFMEA identifies all design functions, failure modes and their effects on the consumer with corresponding severity ranking. Next, it identifies their root causes and mechanisms of the possible failures. High rankings may result in actions to avoid or minimize the causes creating the failure mode. After conducting recommended actions for identified failures, the next step is comparing the before and after RPN values. RPN stands for Risk Priority Number, which is the multiplication of Severity, Occurrence and Detection.
Furthermore, the primary tool used for DFMEA is a DFMEA matrix. This matrix presents a structure for compiling and documenting related information including technical specifications, issue dates, revision dates, and team members. Generally, DFMEA is teamwork of technical expertise and usually includes a cross-functional team. Furthermore, DFMEA does not rely on process controls to overcome possible design failures.
What is the Relationship between FMEA and DFMEA?
FMEA is the generic methodology of Failure Mode Effects Analysis. DFMEA is a type of failure mode effects analysis (FMEA) conducted for the design of products at the design development stage. Both evaluate the possible failures, the severity of the risks, existing controls, recommendations and improvements after recommended actions.
Moreover, the ultimate objective of failure mode effects analysis is to reduce or avoid major lapses of products, processes or services, which will ultimately bring down the cost of design or operation.
What is the Difference Between FMEA and DFMEA?
FMEA is the common terminology for Failure mode effects analysis while DFMEA is a type of FMEA. Furthermore, the key difference between FMEA and DFMEA is their application. FMEA methodology is used for products, processes and services in organizations whereas DFMEA is used only for designs of products.
Summary – FMEA vs DFMEA
The key difference between FMEA and DFMEA is that FMEA stands for Failure Mode Effects Analysis and it is the basis of the methodology whereas DFMEA stands for Design Failure Mode Effects Analysis and it is a type of FMEA.
Reference:
Image Courtesy:
1. “FMEA” By Dieter vandeun – Own work (Public Domain) via Commons Wikimedia
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