Guides
Systems engineering guides
Worked examples of systems engineering practice: how to write a model, a requirement, an interface or a test so that it holds up in review. Each guide stands on its own, whatever tool you use. For how to do each step in Holarch, see the Docs.
SysML v2
The textual notation, definitions and usages, and how a SysMLSystems Modeling Language A graphical modeling language for systems engineering, based on UML, with block, activity, state machine and parametric diagrams. v2 model is built, checked and viewed.
- SysML v2 tutorial: model an electric drive in the textual notation
Build the electric drive of a hybrid car in SysML v2 text, step by step: parts, units, ports, actions, requirements, a verification case and views.
- SysML v2 tools: what to check before you choose one
A vendor-neutral checklist for SysML v2 tools: language coverage, text and views, the API, JSON round trips, v1 migration, plus a test model to load.
- SysML v1 vs v2: how the two languages differ
SysML v1 vs v2 compared: KerML instead of a UMLUnified Modeling Language A standard graphical language for modeling software and systems. SysML is built on it. profile, definitions and usages, text, units, ports, behavior, requirements, views, the API and migration.
In Holarch: SysML v2 projects · language coverage · textual notation reference
Requirements
Writing needs and requirements that can be verified, tracing them, and handling change.
- Requirements traceability: link needs, requirements, design and tests
Requirements traceability explained: trace link types and direction, forward and backward tracing, gaps and orphans, suspect links and the matrix.
In Holarch: needs and requirements · Requirements docs · Traceability docs
Architecture
Functional analysis, decomposition, allocation of functions to components, and physical architecture.
- Functional analysis in systems engineering: from requirements to allocated functions
Functional analysis in systems engineering: derive functions from requirements, decompose them, model the flow and N2N-squared A square chart with elements on the diagonal and what passes between them in the off-diagonal cells. Used to find and check interfaces. interfaces, allocate to components.
In Holarch: behavior · architecture · Functional Analysis docs
Interfaces
Defining what crosses the boundary between subsystems and keeping interface control documents current.
- Interface control document (ICD): what it holds and how to keep it current
What an interface control document contains, who owns it, how to find interfaces with N²N-squared A square chart with elements on the diagonal and what passes between them in the off-diagonal cells. Used to find and check interfaces. diagrams and keep the ICDInterface Control Document The agreed definition of an interface between two systems: what crosses it, how, and who owns it. Holarch also has an Interface Control Diagram. in step with the model, with an example.
In Holarch: interfaces and ICDs · Interfaces docs
Analysis
Budgets, simulation, Monte Carlo runs and trade studies that answer design questions with numbers.
- Trade study example: a weighted decision matrix with sensitivity analysis
A worked trade study example: criteria from requirements, weights, scoring scales, a weighted decision matrix, sensitivity analysis and the recorded rationale.
- Monte Carlo simulation in systems engineering: from point estimates to probabilities
Monte Carlo simulation for systems engineering: input distributions, run counts, percentiles, P(meet), correlation and pitfalls, with a worked timeline example.
In Holarch: Simulation docs · Budgets and TPMs docs · risk and decisions
Verification
Verification methods, test cases, results and evidence, and the verification matrix.
- Requirements verification matrix (RVTM): columns, methods and a worked example
What a requirements verification matrix (RVTMRequirements Verification Traceability Matrix A table of each requirement with how it is verified, the tests that verify it and their latest result.) holds: columns, the four verification methods, plan vs results, failures, suspect rows and an example.
In Holarch: verification · Verification docs
MBSE practice
How a team works from a model: process, reviews, baselines and getting started.
- MBSE example: a CubeSat modeled from needs to verification
An end-to-end MBSEModel-Based Systems Engineering Systems engineering that keeps requirements, behavior, structure and tests in one connected model instead of separate documents. example on a small CubeSat: needs, requirements, functions, architecture, interfaces, budgets, verification and documents in one model.
In Holarch: what is MBSE · SE process docs · LML