MBSE Resources


Essential LML: Lifecycle Modeling Language (LML): a Thinking Tool for Capturing, Connecting and Communicating Complex Systems

A standard Lifecycle Modeling Language (LML) will provide organizations a structured and behavioral language that will provide a simple way to understand and communicate cost, schedule and performance design information to all stakeholders in a standard manner. The combination of a simple structure with appropriate graphical visualizations for every entity class will facilitate the understanding of design for all stakeholders throughout the product lifecycle (concept through disposal). This language will reduce the cost of design and enable more rapid product development to better match information technology and other technical product development timelines.

Essential LML: Lifecycle Modeling Language (LML): a Thinking Tool for Capturing, Connecting and Communicating Complex Systems


Model-Based Systems Engineering De-Mystified

Model-Based Systems Engineering (MBSE) is an ambiguous concept that means many things to many different people. The purpose of this presentation is to “de-mystify” MBSE, with the intent of moving the sub-discipline forward. Model-Based Systems Engineering was envisioned to manage the increasing complexity within systems and System ofSystems. This presentation defines MBSE as the formalized application of modeling (static and dynamic) to support system design and analysis, throughout all phases of the system lifecycle, and through the collection of modeling languages, structures, model-based processes, and presentation frameworks used to support the discipline of systems engineering in a model-based or model-driven context. Using this definition, the components of MBSE (modeling languages, processes, structures, and presentation frameworks) are defined from a language and tool agnostic perspective.

MBSE De-Mystified – 20 Feb 2019


How to Perform a Model-Based Review (MBR)

Since Model-Based Systems Engineering (MBSE) is all the rage today, one aspect of MBSE that often gets ignored is the need to use the database capability to support reviews. Often, we pretend that the modeling tools are there just to produce the documents from the database, but the primary value of MBSE comes from having an interactive medium for reviews as well as the development of the design information.

Below, we show a quick look at how to go about setting Innoslate up to perform an MBR.

How to Perform a Model-Based Reviews (MBR)


The Sellers-Chell Method: A standardized Technique for Assessing and Selecting a Model-Based Systems Engineering (MBSE) Tool

Model-Based Systems Engineering (MBSE) is a growing discipline for applying modeling tools to capture, connect, communicate and control a wide variety of system and project information throughout the life-cycle. A major challenge for engineers and organizations eyeing a move toward MBSE within their projects is the large, and growing, number and variety of tools available. Yet the selection of a specific tool has wide-ranging, enterprise-level implications for an entire organization, potentially influencing, enhancing (or constraining) systems engineering practices and protocols at almost every level. Despite the importance, tool selection is often arbitrary or narrow, focusing on the needs of a single user without wider consideration for the needs of the organization. Surprisingly, few studies have done on systematic techniques to compare and contrast tools in ways that will support organizational selection. The research in this paper describes a standardized technique to help address this problem. The Sellers-Chell Method (SCM) uses the 17 basic Systems Engineering processes described in the NASA Procedural Requirements document 7123.1B as a framework to create an objective “Tool Capabilities Inventory.” The method then asks the assessor to create a simple, pre-defined system model example in the tool under consideration and then perform a “Tool Usability Assessment” derived from the famed Cooper-Harper pilot workload scale. The SCM was used to assess several different MBSE tools and found to have face validity in providing consistent results. While far from perfect, it has built-in flexibility to allow users to tailor it to their specific needs and offers the opportunity for fair and consistent results leading to better fit between a specific MBSE tool and an organization’s needs.

Chell Masters Project-1


The Role of V&V in the Early Stages if the Lifecycle

Verification and Validation (V&V) occur in the later parts of the system lifecycle to ensure that the requirements developed in the early phases of the lifecycle have been met. This paper discusses how to use the techniques of V&V, including simulation, early in the lifecycle to enhance the probability of success of the program by identifying errors early in the development and preparing for the V&V activities later in the lifecycle.

RRY_CM-2


Application of MBSE to Risk-Informed Design Methods for Space Mission Applications

This paper describes research into the application of Model-Based Systems Engineering (MBSE) tools and processes to Risk-Informed Design (RID). RID enables system risk analyses early in the lifecycle of spaceflight projects allowing designers to use risk as a design commodity and part of the overall trade space. RID uses a “minimum functionality” approach, whereby a minimal, single-string system design is first envisioned that only meets basic performance requirements without any regard to overall reliability or safety. Risk analyses are then used to apply informed design enhancements based on their contribution to risk reduction. A recent application of RID was the Altair Lunar Lander Project that was intended for human lunar exploration under NASA’s Constellation Program. The Altair project’s approach and results are reviewed and analyzed in this paper as a specific application of RID. In traditional projects, several tools such as Relex, Windchill or SAPHIRE, are used in parallel to apply risk informed design techniques. These analyses also traditionally occur later in the design cycle when changes are more difficult to implement. Safety and reliability analyses typically have no direct connection with the system architecture model, which accurately depicts the physical and functional constructs of a system, including the “ilities”. The model is directly impacted by the results of the analyses. This creates a time-consuming iterative process of analyses and modification because of the need to integrate several tools and teams. To improve this process, the research described here investigated the use of a single, cloud-based MBSE CAD tool called Innoslate that integrates failure analysis into the system architecture model. The specific focus of the research was on the analysis of system failure events through the use of a system architecture-modeling tool and the establishment of an MBSE process that enables system engineers to make risk-informed system modifications during development. The conclusion of the research was that MBSE in general, and Innoslate specifically, is capable of providing an integrated, effective and quantitative means of developing a risk-informed system design using a minimum functionality baseline process. This can be applied to human and robotic spaceflight systems and other systems with similar complexity. The research demonstrated that random distributions could be added to failure probabilities in order to add “noise” to the results, a task that can be laborious, if not impossible, if performed using a calculator or spreadsheet. The research also demonstrated an end-to-end MBSE process that was applied to a basic system model and the Altair Project. Recommendations for future work conclude the paper.

SYS 800 Research Paper_Rafael Perez_Dist


Defining Essential Systems Engineering using Model-Based Systems Engineering

This research presents a new approach to simplify the implementation of systems engineering using model-based systems engineering tools. The concept of systems engineering facets is introduced to provide a framework for identifying and grouping related systems engineering activities, deliverables and assessments throughout a project lifecycle. Collectively these are referred to as essentials within the research. The project management and systems engineering processes are analyzed to identify the essentials, and are then organized by facets. Next, using a model-based systems engineering tool this information is stored in a central location called a Systems Engineering Lifecycle Template. The purpose of the Systems Engineering Lifecycle Template is to tell the story of a project from start to finish by clearly capturing, connecting and communicating all of the essentials required to enable the realization of the system. The template is a living document within the MBSE tool that is updated regularly by the project team as essentials are completed and serves as the starting and ending point for all systems engineering related activities. The motivation for this research is the NanoMet academic case study. NanoMet is a 3U CubeSat platform developed jointly by the USAF Academy Department of Astronautics and an Industry team. It is used in classrooms around the world to teach space systems engineering and to provide a complete mission lifecycle experience. Every aspect of NanoMet is modeled using the MBSE tool Innoslate. Innoslate is based on the open-source Lifecycle Modeling Language (LML). NanoMet uses the NASA Procedural Requirements for its project management and systems engineering processes. This research was developed in response to a need to organize the NanoMet system model, teach MBSE methodologies and help systems engineers transition from document-centric systems engineering methodologies to model-based systems engineering methodologies. The research concludes by providing the framework and guidance to applying the new approach to the NanoMet system model in Innoslate. The goal of this research is to simplify systems engineering by developing the modeling tools and approaches necessary to effectively use model-based systems engineering, and to provide a project team with an effective method to communicate vital information about a project. A successful project is one that can effectively communicate and this research provides a method to achieve success.

SYS 800 Defining Essential SE using MBSE – Steven Orosz-1