Have you recently created 2D and 3D drawings of a product you’re looking to manufacture and launch into the market, or do you plan to modify the manufacturing operations of your supply chain? If so, you need to understand that failures are bound to happen—whether during manufacturing or after launching the product.
However, the sooner you discover these failures, the less they will cost you down the road. One methodology that has helped many successful businesses detect possible failures and mitigate risks while designing a product is FMEA (Failure Modes and Effects Analysis).
But what is FMEA, and how do you implement it during your new product introduction (NPI) process? This article will get to the basics of FMEA and provide you with a simple FMEA example. By the end of this read, you’ll have enough information to help you create one for your manufacturing project.
––––––––––––––––––––
––––––––––––––––––––
What is FMEA, and When Should You Use It?
Failure Modes and Effects Analysis (FMEA) is a systematic method for identifying potential failures in a product or process.
Look at it this way—during an FMEA, you will review components, assemblies, sub-assemblies, and assembly lines to identify possible failure modes, so you can take steps to eliminate them.
To help better understand FMEA, let’s break down the essential words that make up “Failure Modes and Effects Analysis.”
Failure Modes: describes the ways (or manner) in which your products can fail.
Effects: describes the undesired effects that you (and your customers) may experience due to these possible failures.
Analysis: describes all the measures taken to identify the causes, frequency, and severity of these failures.
As simple as FMEA might seem, significant planning and effort go into making your FMEA effective. It starts with you knowing the type of FMEA to perform and at which stage of the new product introduction process you need to complete the FMEA.
Failure Modes and Effects Analysis comes in two types:
Design Failure Modes and Effects Analysis (DFMEA)
Process Failure Modes and Effects Analysis (PFMEA)
Design Failure Modes and Effects Analysis (DFMEA)
DFMEA helps you identify and mitigate potential risks in your product's new (or modified) design. It looks at your design from functional, performance, and longevity perspectives.
For example, your engineering material choices, tolerance specifications, and product geometry will significantly impact your product’s performance and service life. As such, you need to discover the risks associated with your product design to ensure that it meets your requirements and customer needs.
As a rule, you must perform DFMEA very early during the design phase of your new product introduction process.
Process Failure Modes and Effects Analysis (PFMEA)
A Process FMEA simply helps you to identify human factor errors and failures associated with the methods, materials, machinery, and measurement systems involved in a process.
Look at it this way. A PFMEA firstly helps you determine whether your product is manufacturable. And if it is, a PFMEA enables you to identify the kinds of problems (or risks) you’re likely to face during the manufacturing process.
This analysis gives you insights into managing these risks, including planning for the manufacturing and design changes you need to implement. Unlike DFMEA, you should perform PFMEA when getting ready for production.
FMEA Example: Automated Teller Machine (ATM)
Figure 1 shows a typical FMEA example of an Automated Teller Machine (ATM). In this FMEA example, we will be considering only the cash withdrawal function of the ATM. Let’s fill out the possible failure modes and assess the risks associated with the “cash withdrawal” function.
Fig 1. FMEA Example of an ATM
Note: To help you better understand this FMEA example, we’ll be presenting additional images, all of which we cropped from Figure 1. So you can always refer to Figure 1 to have the full view.
FMEA Example: Failure Modes
Column B shows the possible failure modes when a customer tries to withdraw an amount from the ATM. Likewise, column C shows the impacts of that failure on you (and your customer). (See Figure 2)
Fig. 2 Failure Modes and Effects Analysis
For example, the failure mode “Account debited but no cash disbursed” will likely cause you to have discrepancies in cash balancing as well as a very dissatisfied customer.
The impact of every potential failure mode is evaluated by what is called Severity—it describes how severe the effects would be should the potential risks occur. Severity is typically rated between 1 and 10, with 10 being the absolute worst (or most severe) and 1 having a negligible effect.
For example, you’d agree that things would be more severe for you if, say, your ATM dispenses too much cash than requested than when your ATM doesn’t dispense to your customer. So we could assign a severity number of 8 to the former scenario and 7 to the latter.
But that’s not all there is to risk assessment in FMEA.
FMEA Example: More Risk Assessment with Subject Matter Experts
The truth is that anyone can come up with a list of potential failure modes and effects. But if you’re going to perform an FMEA that works, you need a cross-functional team (CFT) of subject matter experts, preferably with at least 15 to 20 years of experience.
These experts will use their expertise to perform the following:
Identify the potential causes of the failure modes.
Rank how often the cause of failure modes occur (see Column F).
Identify the current process controls of the failure modes.
Rank how likely you’re going to detect the failure mode with the current process control before it affects your customers (see column H).
All these are represented in columns E, F, G, and H as “Potential causes,” “Occurrence,” “Current process control,” and “Detection,” respectively in Figure 3.
Fig. 3 Risk assessment with subject matter experts
The combined impact of “Severity,” “Occurrence,” and “Detection” is the Risk Priority Number (RPN)ㅡit is the calculation of the risk of a particular failure mode. You can calculate RPN by simply multiplying the Severity (S), Occurrence (O), and Detection (D rankings), as shown below:
RPN = Severity * Occurrence * Detection
Risk Priority Number (RPN) allows you to prioritize the items which need additional quality control planning. For example, from the FMEA example, you can see that the failure mode “Does not dispense cash” with a potential cause of “ATM out of cash” has the highest RPN. Therefore, it warrants further review (and control plans) by you and other subject matter experts.
In contrast, the failure mode “dispenses too much cash” has the lowest RPN of 48. But it might still warrant further investigation since the RPN is high at 48.
Failure Modes and Effects Analysis: Agile in Asia Can Help
Now that you know the basics of FMEA, you can go ahead and perform an FMEA for your product, right?
While FMEA looks relatively straightforward, sometimes the process of filling on out can become a nightmare. We often perform these with our clients and find that a complete FMEA can cover a paper size as large as A0 (33.1 x 46.8inches).
If you’re going to perform an accurate FMEA that captures all the possible failure modes in your design or process, you need a cross-functional team (CTF) of subject matter experts. These experts should have at least 15 - 20 years of experience to ensure that you don’t miss anything. An expert team will help you review your design thoroughly and determine RPNs and form and implement corrective action plans, allowing you to get your product done right the first time.
Agile in Asia is a leading provider of risk assessment solutions across the globe. We have a team of highly qualified engineers, manufacturing experts (covering many manufacturing processes), and supply chain experts. We help businesses to perform thorough DFMEA and PFMEA, reducing their risks when bringing a new product to the market.
Learn more about our new product introduction services.
Comments