The Case for Generic FMEAs and Strategies for How to Use Them in Xfmea
As product development to market times continue to shrink, the amount of allowable time to perform efficient FMEAs and follow best practices for design review similarly is reduced. One strategy for maximizing effective use of time and efforts is to intelligently and appropriately reuse FMEA and system configuration information from previous generations or platform siblings. This article discusses several ways that you can use the Xfmea software to manage and use various approaches for storing and reusing your FMEA data.
Generic FMEAs take many forms and approaches. Choosing the method that is best for you requires understanding the strengths and risks for each approach. Among the many ways they can be used, one common method is to continuously update partially filled out FMEAs with captured lessons learned from previous analyses. This approach is typically used to populate lists of common FMEA definitions (functions, failure modes, effects, etc.), or can be used to represent common piece parts in systems. This is most effective where we can safely assume that these parts are functionally identical wherever they are implemented.
Other methods allow you to recreate, or selectively manage and reuse not only FMEA elements, but also portions of or the entire system hierarchy/BOM structure. Others allow you to manage and reuse only the elements that are appropriate for the next generation of your design. And yet others give you centralized control and management of common equipment to a single instance that you can reuse in many different areas or projects.
With any approach where you are reusing previous assumptions and information, your team should have a standardized approach for assessing the appropriateness for reuse, and then for reviewing the reused material with a set of questions and common concerns.
Using the Smart Add feature within Xfmea allows you to build system hierarchies and FMEAs from prior projects of preconfigured structures. Effectively this means that Xfmea can identify common structures and associations from existing analyses. Additionally, the Smart Add feature enables you to easily apply FMEA elements into your analysis based upon identifiers matched to previous projects.
In this manner you can rebuild portions of a hierarchy, either mirroring previous configurations or building a hierarchy via a more modular approach if many similar configurations have been introduced or set up. Once you establish the hierarchy, you can continue to use the Smart Add features to bring in FMEA elements (functions, failure modes, effects, etc.) based upon prior use and matching identifiers as appropriate. Figure 1 shows how you can import failure descriptions that match the specified criteria.
Figure 1. Smart Add Example
One of the primary strengths of this approach is that you can see all possible previously used or configured options, and then select the ones that are most appropriate for the current design. Since you can select and add many options at once, this can significantly speed up the pre-population step for FMEA preparation/facilitation.
The ability to link and manage FMEA analyses from reference projects allows companies with multiple design FMEAs of similar systems to control common subsystem and component level FMEAs from one centralized location. You can then reuse these FMEAs in as many active projects as necessary. Additionally, you can use this approach of defining once and reusing in many places in other approaches where you can assemble FMEAs in a much more modular or process-driven environment.
When linking from a reference project, the entire common FMEA is re-used in the new location, and you can also add unique local FMEAs for any applications or functions that vary from the common FMEA. Due to the limitation of reusing each analysis in whole, you need to strategically approach how you structure these analyses. There are two primary methods for doing this.
- Define the generic function-failure-effect-cause-control chains so as to only capture those functions and following definitions that can apply across the intended range of reuse.
- Break down function-chains into a much more modular approach, where you have multiple analyses to pull from to assemble any given FMEA. For example, you could break them down where one level contains common design requirements, and then have different platform applications based on usage criteria, material specifications, environmental considerations or adherence to specific standards.
Either of these approaches will still require evaluation from the team post-assembly or reuse to consider whether there are additional FMEA records that the team is required to address or where concerns remain. In this case, Xfmea offers multiple methods of resolution. You can add a local analysis to the item where you have the FMEA. This method allows the team to define additional concerns while still maintaining an active link to the reference project source. Alternatively, the team can break the link to the originating reference material, thus allowing the team to modify the information as they would any other standard FMEA approach. Figure 2 shows an item with both a local FMEA and a linked FMEA from a reference project.
Figure 2. Item with Local FMEA and Reference FMEA
The concept behind using restore points is to reduce your system configuration, and each FMEA within your system, down to the basic requirements and common approaches, and then use that as your starting point for your next revision. This requires maintaining and updating the baseline after each completed FMEA. However, it also has the strength of completely carrying over your system configuration (BOM) as well as common requirements, functions, failure modes and beyond.
There are a myriad of ways to import information into Xfmea to reuse, or utilize information that is either inside the repository, coming from another ReliaSoft application, or from external sources. In this way you can use existing Excel documents, prior Xfmea projects or external databases as potential starting points. The internal reuse from within Xfmea grants you the most flexibility, with methods to pull in selected hierarchy items and/or portions of, or entire FMEA analyses, along with filtering criteria, and search features. Additionally, you can import the BOM and reliability data from a prediction completed in the Lambda Predict software or build from the systems that are represented in XFRACAS. Figure 3 shows two ways of importing data from other projects from within Xfmea.
Figure 3. Import Examples
As stated above, there are many methods that you can follow to appropriately reuse information to help guide your FMEA process and allow your team to focus on where the identified risk is and, with minimal vetting effort, help to develop a strategy for a design process that continuously improves itself with every new generation of FMEA.