Author: Tim Weilkiens

SysML activity tree with object nodes

Hidden feature of SysML – Activity Trees

It is very well unknown and I know only a single modeling tool that explicitly supports it: the SysML activity tree. Although it is very useful and supports common systems engineering practice. What am I talking about? You may know use cases and activities to describe the use case flows. Simply spoken they describe the…
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Structure of a SysML model with metadata Issues, Notes, and Sketches

Metadata in the model

Models do not only contain the “real” artifacts for your system, but also additional auxiliary information like notes, issues, images, and so on (metadata). It is very useful to store such information at the place where you need or create it. Switching from one tool to another is a hurdle that prevents people from looking…
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Extended system context with SysML - FFDS example

How to model an extended system context with SysML

The extended system context describes the system interfaces and the detailed connection to the system actors and to the internal parts of the actors. In the previous post How to model a simple system context with SysML I’ve written about system context in general and the simple edition of system context that is simply spoken just…
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System context Forest Fire Detection System with SysML

How to model a simple system context with SysML

The system context defines the system boundary and all system actors – humans and external systems – that interact with the system under development. It is one of the most important parts of the system model. Many artifacts of the system specification and architecture are relative defined to the definition of the system. Every system behavior…
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SYSMOD Zigzag Base Architecture - FFDS example

The Base Architecture

How to relate requirements and architecture on different abstraction levels The SYSMOD zigzag pattern describes the different levels of abstractions and the relationship between requirements and architecture. Your system requirements do not start at the very top of the levels, i.e. they already include some technical decisions. The base architecture is the architecture one level above…
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System configuration in MagicDraw

How to select a single configuration from a variant model?

In a previous post I’ve described an approach how to model variants with SysML (Variant Modeling with SysML). Modeling variants leads to a model that represents a multidimensional configuration space. It is a description of each variant, the common elements and the relationships between them in a single model. A single configuration is a valid…
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SysML 1.3 / SYSMOD Reference Card (English)

SysML 1.3 released

The OMG has published the new SysML version 1.3. The specification document is available on the OMG website. You can also download a version with change bars to see the differences to the previous version. The new version reflects feedback from the industry using SysML. In the SysML working group we’ve done major changes to…
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Structure of a SysML model

Structure of a SysML model

On the first view it seems to be simple to define the package structure of a SysML model. However you’ll often get problems with a implicit built structure. A model has many – orthogonal – aspects and abstraction layers that could be mapped into the package structure, e.g. domain, modeling, or organizational aspects. You can…
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SysML Matrix Example: Functional groups of the FAS method (source: http://www.fas-method.org)

New views for SysML

I often hear arguments against SysML that the diagrams are not suitable for the stakeholder concerns. For example it is not a good idea to choose the requirements diagram to show thousands of requirements or a block definition diagram to show the complete mapping of the functional to the physical architecture with allocate relationships. It…
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Variant Modeling with SysML

Many systems exist in different configurations. A product line, a custom product or different designs for trade-off studies. The current version 1.2 of SysML doesn’t provide explicit built-in language constructs to model variants. The profile mechanis of SysML can be used to extend SysML with a concept for variant modeling. I’ve defined a simple variant…
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