It might sound easy to maintain equipment that was originally designed and developed years (or decades) ago. However, as supply chains evolve and change over time, so does the availability of crucial aspects of the Bill of Materials for a particular part.
We wouldn’t be able to continue building these legacy systems without a dedicated approach to Configuration Management & Revision Control.
Military Handbook MIL-HDBK-61A(SE) defines configuration management (CM) as “a process for establishing and maintaining consistency of a product’s performance, function and physical attributes with its requirements, design and operational information throughout its life.”
Essentially, configuration management & revision controls mean that care is taken throughout the product lifecycle to ensure that the product will perform the same functions in the same environment as its predecessors and successors. This is called a Form, Fit, and Function replacement, or FFF.
The most common use case for a Configuration Management & Revision Control policy in the electronics industry is when a sub-component (for displays, something like a video controller or an LCD panel) go End-of-Life (EOL), meaning that the component is no longer offered or supported by its manufacturer.
However, just because a component is End-of-Life doesn’t mean your program is.
What a robust Configuration Management & Revision Control policy does in these circumstances is maintain product continuity in the case of component obsolescence.
Let’s take an example ECN (Engineering Change Notice) log for our P/N 90-700-058, which is now on its 10th iteration:
| Rev | Date | Reason |
|---|---|---|
| — | 11/21/00 | Initial Release |
| A | 4/13/01 | Updates for production |
| B | 9/14/01 | Update rack mount sleeve per customer request |
| C | 10/2/03 | Add cable guide per customer request |
| D | 5/18/05 | Update video controller due to EOL |
| E | 11/30/06 | Update LCD due to EOL |
| F | 10/16/09 | Update LCD due to EOL |
| G | 5/21/10 | Update LCD due to EOL. Update video controller due to EOL. Update backlight inverter due to EOL. |
| H | 5/2/13 | Gloss rating of glass overlay updated due to availability of existing overlay |
| J | 6/7/19 | Update LCD due to EOL. Update video controller due to EOL |
The first few revisions (-A, -B, and -C) did affect the product functionality slightly, but as the part was custom-designed for a single customer and hadn’t yet been sold elsewhere, we maintained the revisions on the original baseline part to make it easier for our customer.
This example illustrates that the base part number (no revisions) is not always the gold standard or baseline configuration. As the product undergoes customer evaluation and field testing, it may require modifications to the configuration to optimize its performance.
Of course, all of these changes were customer driven and approved. In the example above, the 90-700-085-C represents the finalized baseline configuration, to which all future configurations are compared.
This means that everything from -D to -J is a FFF replacement to the -C. Over the course of 18 years, through eight EOL announcements and one availability issue, we’ve maintained this part number for our customer.
In fact, in 2014 we created a replacement to the 90-700-058 (which saves rack space and improves graphics) and introduced it to the market. Since it wasn’t a FFF replacement to the 90-700-058, we introduced a new part number (P/N 90-2717-001) that is used on contemporary programs.
However, those few customers who purchased the older system cannot justify ordering the new system, for reasons we will discuss below. That means that on top of supporting this part for 18 years, for the last 7 years it has been a technically inferior, obsolete solution that we maintain because it is what’s best for our customer.
That’s Configuration Management & Revision Control.
The ANSI/EIA-649 Standard for Configuration Management summarizes the benefits of CM from an industry viewpoint, as follows:
It’s no secret that defense and government buyers are price conscious. They want to pay the lowest possible amount for a product that does exactly what they need, and are not interested in upgrading it every year, unlike those who must have the latest iPhone model.
To that end, our engineers have implemented a modular design process to make it easier to replace components when obsolescence issues arise.
By reducing the impact of forced design changes due to obsolescence issues, we significantly extend product life cycles and lower the non-recurring design change expenses (NRE) by making it easier and more cost-effective to customize products to meet specifications.
By providing a FFF replacement with complete documentation support, the product may not require recertification and its associated costs, and thus reduces the total lifetime cost of the program.
If there are associated redesign costs, or if the change to the Bill of Materials is deemed too significant to qualify the new revision by similarity, our customers still have an opportunity to place a Last Time Buy to reserve stock of the component for future builds.
This all alludes to the ultimate benefit of our approach to configuration management and revision control—reduced total cost of ownership. By providing last-time buy options, backwards compatible replacements, and reducing or eliminating the need for recertification, redesign, and re-documentation, we offer something that traditional COTS manufacturers cannot—a partnership instead of a product.
Over the past 50 years, we’ve found that this approach allows us to fill a vital role in the defense and government markets. Other companies do not take the same dedicated approach to design life cycle configuration that we do. Your 10 pc or 100 pc order is just a rounding error to a massive consumer-focused electronics manufacturer. To us, it’s our core business model.
Being a private, family-owned company, we are able to make decisions that are better for our customer. We understand that dedication to Configuration Management & Revision Control means that we don’t just stand behind our products, we stand behind the end user’s programs our products support. And it is an honor to work for you.
