Article by AL.com – March 2021- Customers in the aerospace and defense sector expect speed, precision, and transparency in systems development. Achieving these objectives with a Document-Based Systems Engineering (DBSE) approach is a challenge. Risk can increase exponentially in complex systems as each adjustment in system requirements or design must be traced across multiple documents and engineering products. Model-Based System Engineering (MBSE) solves this problem by managing and storing system information within the context of a system model. This model allows System Engineers and designers to identify changes in real time and trace the ripple effect of those changes throughout the system. Still, many firms are not experts in MBSE—why? Transitioning from a document-based approach to a model-based approach is a lot like going from keeping a list in MS Excel to developing an SQL database. MBSE requires specialized skills, including proficiency with the Systems Modeling Language (SysML). Building those skills requires significant investment and a long-term commitment. For Intuitive Research and Technology Corporation (INTUITIVE), making that investment was an easy decision. The hardest problems in systems engineering (the kind INTUITIVE targets) are those with the most layers of interdependent operations – the very ones that benefit the most from MBSE.
Where is the Risk in Systems Projects?
INTUITIVE uses MBSE to lower overall risk. They do so by creating a single dynamic model of all interrelated systems that serve as a source of truth for the project. This model documents the system requirements describes how the system will be assembled to meet those requirements, and list the lists the verification and validation activities needed to ensure the system meets its requirements. Here are the keyways MBSE limits risk and gets it right:
Better Communication
Models are created to deal with complexity. In doing so, they allow us to understand an area of interest or concern and provide unambiguous communication among interested parties. Built around a common language, the models eliminate ambiguity and promote a shared understanding between users, project offices, and the development teams. According to Jordan Mills, one of INTUITVE’s Model-Based Systems Engineers (who works with the Army Agency, CoMBAT – Center of Model Based Acquisition and Technology) “All elements are stored in the model, but specific diagrams are created for specific purposes. MBSE allows one to create different views for different stakeholders depending on the particular party’s interests and the message that is wanting to be conveyed to the viewer.” In short, a model-based approach houses all system information in a single model using an agreed upon language. When compared with a traditional approach where system information is stored in dozens of documents with less agreement on what the language means, MBSE dramatically improves the speed and clarity of communication across the design team.
Improved Efficiency
DBSE teams can produce models, but they are static models that are circumscribed to one variable. Because of this, they have a difficult time capturing the effect of changes on system operation. Further, information gets pushed from one document to another creating redundant entries and the possibility of transcription errors.
Because MBSE houses all system data in a single model, there is no need to transfer information from one system or document to another. This eliminates redundancy and the opportunity for copy and paste errors. According to Mills, “A central concept of MBSE is the idea of reuse. An element is created once and reused throughout the model. This re-use of information allows system information to be more consistent and saves engineers valuable time when developing systems.” She noted that MBSE’s visual or graphical approach makes the systems engineering process cheaper and faster.
A graphical approach also means MBSE limits costly rework by helping engineers consider the impact of design changes before the system design is complete. Further, this allows more flexibility in exploring alternative solutions without consequence. MBSE exposes system defects early when they are cheaper.
Ongoing Utility
Far more than product specs or just testing, “MBSE can be used throughout the systems engineering lifecycle for a project. Commonly, models are used to develop system architectures, model system behavior, create and store requirements, and perform gap analyses for projects,” said Jason Rogers, an INTUITIVESenior Model-Based Systems Engineer supporting the Army’s CoMBAT team. The defense and aerospace industries are increasingly relying on the use of digital engineering approaches. Rogers explains, “With the increasing amount of information that engineers are required to analyze, the traditional document-based approach is becoming more difficult to sustain.” MBSE matters because it provides an effective way to manage system complexity.
Here is how INTUITIVE has used MBSE in past projects:
- Developing models for PEO AVN, PEO M&S, MDA, Navy, and NASA.
- Developing Architecture Models and Requirements for NASA’s Vision for Space Exploration (VSE) including requirements derivation, evaluation, and analysis for a full Space Architecture.
- Developing the overarching model for the UAS Family of Systems (FOS) including the incorporation of novel modeling techniques to describe the requirements associated with Air-Launched Effects (ALE).
- Applying MBSE to legacy systems such as the UH-60 Avionics system and the HELLFIRE Missile.
- Developing the MBSE approach and models for the Navy’s Low Altitude Range Communication System (LARCS).
MBSE As a Company Priority (Not a Passing Phase)
Using a model-centric approach, the model serves as a central database for system information. According to Mills, the model becomes the ‘source of truth’ for the various stakeholders or organizations involved. “A common myth is that MBSE is done as a side project and is not part of the real systems engineering process, but MBSE is just systems engineering using models,” she said. “MBSE is supposed to be applied throughout the system’s life cycle.” She further noted that modeling tools are only as good as the engineer who develops the system and writes system requirements.
A literature review of 21 case studies published by Sandia in 2016 concludes “An MBSE approach made the engineering processes on a complex system development effort more efficient by improving requirements completeness, consistency, and communication,” but only if enterprises made investments and commitments such as the following (i.e., treating the system as the source of truth):
Prerequisites
- Mature, well-documented, and enterprise-wide SE processes that span the system lifecycle
- Systems engineers trained in MBSE techniques
- Access to training in the SE processes for all engineers
- Defined processes for model management throughout the system lifecycle
- Investment in full-scale MBSE tools
Commitments
- Initiate modeling with appropriate staffing levels at the beginning of the program
- Ensure model configuration management – “When changes occur after a baseline of the model, so does the configuration of that model which represents the system’s design.”
- Provide continuous resources to maintain the models throughout the system lifecycle
- Provide MBSE resources and models to support system testing, qualification, and V&V
- Provide appropriate sustained computing infrastructure throughout the system lifecycle
Systematic Learning Makes the Difference
INTUITIVE has developed an MBSE Computer-Based Training course offered to new or MBSE-inexperienced employees, current employees, and customer counterparts. “INTUITIVE believes that when we invest in training that supports our employees’ career development, we can retain the talent the company needs to better support our customers,” said Rogers. “Engineers from other backgrounds may also take the course to have a better grasp of complex system development as needed.” He continued, “INTUITIVE’s customers also depend on our training services to help influence the transition of a traditional DBSE approach to an MBSE approach.” INTUITIVE has established an MBSE Community of Practice within the company. This Community of Practice is employee led and focused on developing MBSE capabilities across the organization by providing regular training, a collaborative learning environment, and a place to go to ask questions when dealing with a particularly thorny modeling problem.
Give the Right Team the Keys to the Model, They’ll Drive Better Results
“MBSE optimizes the design of various military aircraft, drones, missiles, and radars so that the military can have better end products. MBSE can help improve system development for a wide spectrum of systems in a variety of fields,” concluded Mills. In the case of a complex system project, your first choice for a partner should demonstrate company-wide investments in MBSE and be able to present completed industry-relevant projects. INTUITIVE is the best partner for this pursuit.
Learn more about INTUITIVE’s Model-Based System Engineering capabilities by clicking here today.