In Episode 71 of Razorleaf’s Stay Sharp podcast, Bridging MBSE and PLM: Overcoming Challenges in Digital Engineering, co-hosts Jonathan Scott and Juliann Grant welcome returning guest Pat Coulehan, a colleague from Razorleaf Government Solutions. Pat joined the duo recently—in Stay Sharp Episode 69—to explore the benefits and challenges of taking shipbuilders through a digital transformation. Another project Pat is involved in is a large model-based defense program, which makes him the perfect person to discuss the growing interest in model-based systems engineering (MBSE), as well as how MBSE intersects with product lifecycle management (PLM) systems.
The Basics of MBSE and PLM
Jonathan and Pat begin by making it clear that MBSE is an approach to systems engineering that can be supported by various tools or systems. (Learn more about MBSE in Stay Sharp Episode 32.) In contrast, PLM is a system, Jonathan explains, “not single tools, but enterprise systems that manage product data over its lifecycle.” PLM platforms, as well as product data management (PDM) software, manage processes, data, models, and other kinds of information.
While the MBSE movement has grown in the last five to 10 years, Jonathan feels that it’s just now coming into its own in the defense space. He compares MBSE to software data management, due to its collaborative tools that depend on branching and merging. Pat agrees, “Because it’s dealing with a lot of people working on a project at the same time, it’s like a software project.”
Putting MBSE and PLM Together
While it might seem like an enterprise system that has the scope of PLM could easily manage the approach of MBSE, Pat cautions that PLM systems don’t understand—meaning they can’t access or represent—all the complexities of MBSE’s details. “It can manage the model, but it’s not necessarily managing all the internals of the model,” he says, “because it doesn’t have that level of understanding of the different frameworks and what those objects are in each of those frameworks.” Jonathan chimes in with the example of a model of an automobile. “Although PLM could maybe manage the MBSE file that’s got all these elements in it for the motor, the tires, the chassis … to be able to reach in and know that the motor element with its attributes and behaviors is the same as that motor that’s in a bill of material or that 3D model file, that’s where the challenge is.”
The other point to consider about the intersection of MBSE and PLM is that communication in both directions is important. You’re not just passing systems engineering information down to the detailed design, Pat says, “You also have that feedback loop, where now that you have the actual design, how do you get that information back in to make sure it’s meeting the requirements and the functionality that you designed in your system model.” He adds, “You really have to think about use cases and say, this is what I need to be able to send this information back.”
Planning Your MBSE/PLM Project
Pat offers a handful of tips for what to consider when starting to plan an MBSE project or to use MBSE with PLM, starting with understanding what you’re trying to accomplish. MBSE won’t solve every single problem, so what’s important is, “managing the expectation of this is what we want to do with it.” He continues, “This is what we want to get out of it, this is how we want to use it … and saying, we’re going to crawl, walk, and run.”
Planning should also include thinking about how you’ll want to handle configuration management, requirements management, and change management—understanding that you might want to manage some aspects of each in different systems. Pat also points out that how you do a process can change over time. “You’re going to do a couple [things] the wrong way the first few times,” he says, “and then you’re going to refine your methodology as you go.” To avoid pitfalls, he reiterates the idea that up-front planning is essential. “You have to have your standards and your framework and your methodology nailed down before you get too far into it,” he explains.
Learn More About Using MBSE and PLM
The full podcast contains more discussion and details on a variety of topics, including why MBSE and PLM activities have different speeds, how PLM systems handle the challenges of configuration management better (so far) than MBSE tools, why you might want to do different parts of requirements management in different tools, and more.
Check out the full conversation in Stay Sharp Episode 71: Bridging MBSE and PLM: Overcoming Challenges in Digital Engineering, as well as the trio’s first conversation in Stay Sharp Episode 69: Navigating the Digital Seas of Shipbuilding. And join us each week for a new podcast.
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