Ask three engineers on the same program where the authoritative version of a requirement lives and you'll often get three answers: the DOORS module, the SysML model, and "whatever was in the last review package." All three are wrong in the same way. None of them is authoritative because nobody decided, and enforced, which one consumers must reference. That gap is exactly what the phrase "authoritative source of truth" is meant to close, and it's why the term keeps showing up in defense acquisition language even though it sounds like plumbing.
DoDI 5000.97, the Department of Defense's digital engineering instruction issued in December 2023, made the idea policy. It directs programs to use digital engineering practices and leans on the digital thread as an authoritative source of truth for digital artifacts. The instruction applies to defense programs with few exceptions, so for a lot of suppliers this stopped being a philosophy question and became a contract question. But the policy describes an outcome, not a product you can buy. Getting to an actual ASoT is mostly about how a team behaves, not which repository it licenses.
What DoDI 5000.97 actually asks for
The instruction builds on the 2018 DoD Digital Engineering Strategy and its five goals, the first of which was to formalize the development and use of models to inform decisions. DoDI 5000.97 turns that intent into direction for program managers: implement digital engineering, use authoritative models and data as a continuum across the lifecycle, and connect those artifacts so decisions trace back to something real.
What it does not do is mandate a specific tool, schema, or vendor. That's deliberate, and it's also where teams get into trouble. Reading "authoritative source of truth" as "buy one big database and put everything in it" misses the point. The DoD's own framing describes an ecosystem, a connected set of authoritative sources rather than a single monolithic store. The instruction cares that the data is governed and traceable, not that it all sits in one place.
What an authoritative source of truth is, and isn't
The cleanest definition in circulation comes from the U.S. Space Force, which describes an ASoT as the single, definitive source of a given piece of information that all consumers should reference, so nobody relies on outdated, inconsistent, or inaccurate copies. Read that carefully and the operative word is "reference." An ASoT isn't defined by where data is stored. It's defined by the rule that everyone points at the same governed instance instead of making private copies.
That distinction matters because most engineering organizations already have the opposite. A requirement gets exported to a spreadsheet for a meeting, pasted into a slide, restated in a model, and summarized in a memo. Now there are five versions and no way to know which one a given person was looking at. An ASoT exists when that copying stops being the norm: the requirement has one configuration-controlled home, every other artifact links to it, and a change in one place is visible everywhere that references it. The OMG MBSE community frames this around traceability over time, capturing historical knowledge and connecting configuration-controlled versions of models and data as the system evolves.
So an ASoT is not a repository, a PLM seat, or a SysML tool. It's a governance commitment that those tools can support. The technology is necessary but it's the easy half.
The hard part is governance, not storage
Standing up the storage is a procurement task. Making an artifact genuinely authoritative is a discipline, and it follows a repeatable shape for every piece of information you want to trust.
Each step is where programs quietly fail. Authoring happens fine. Configuration control often doesn't, because the model lives on someone's workstation or in a branch nobody merges. "Connect, don't copy" is the hardest cultural shift, since exporting to a spreadsheet is faster today even though it destroys traceability tomorrow. And the final step, getting people to actually reference the governed source instead of the convenient copy, only holds if leadership treats the copy as the error it is. None of that is a tooling feature. It's process, ownership, and the willingness to make the right path the easy one.
Where the tools fit
Tools earn their keep by making the connected, configuration-controlled version less painful than the copy. SysML and related modeling environments help by giving engineering information a centralized, linked home rather than a pile of documents. Dassault's Cameo Systems Modeler ties models into the broader 3DEXPERIENCE and Teamlab data backbone, Eclipse Capella pairs an Arcadia-method modeling environment with team collaboration through its Team for Capella server, and Dalus is a SysML v2-native platform that stores models through the standard's API. Each takes a different path to the same requirement: a governed place where elements are versioned and other artifacts can point at them instead of duplicating them.
The detail worth checking before you commit to any of them is how the model connects outward. An ASoT spanning requirements, architecture, simulation, and test only works if those repositories can reference each other through stable identifiers and open interfaces. A tool that holds your architecture beautifully but can't expose it to the requirements or PLM system isn't an authoritative source of anything beyond its own walls. Interoperability, not internal polish, is what determines whether a tool can participate in an ecosystem ASoT.
What an ASoT won't solve
It won't fix bad data. If your requirements are vague or your model is wrong, making it authoritative just gives everyone one confident place to be wrong together. Governance enforces consistency, not correctness.
It also won't eliminate the human work of curation. Someone has to own each authoritative source, adjudicate conflicts, and decide what gets promoted to authoritative versus what stays a working draft. That role is real labor, and programs that expect the tool to do it discover the gap during their first messy change request.
And it won't deliver value the day you flip it on. An ASoT pays off over the lifecycle, through change impact analysis, audit evidence, and the ability to answer "what did we know and when" years later. Early on it can feel like pure overhead, which is precisely when underfunded efforts get abandoned. The honest trade is near-term friction for long-term traceability, and that trade only makes sense if the system has a long enough life to collect on it.
The bottom line
The authoritative source of truth is one of the more useful ideas in digital engineering and one of the most over-sold. DoDI 5000.97 made it policy for defense programs, but the policy describes governed, connected, traceable data, not a product. The tools matter, and choosing one with open interfaces matters more than most teams think. What matters most is the unglamorous part: deciding who owns each source, making references the default instead of copies, and funding the discipline long enough to reach the lifecycle stage where it pays back. Buy the repository if you need it. Just don't confuse it with the practice.