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Webel - in operation in Australia since 2000 - is a Scientific IT Consultancy, specialising in model-driven software engineering and systems engineering for tasks in science and engineering using technologies such as:

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Proprietor Dr Darren welcomes you to Webel - the "Elements of the Web"

SysML Package Diagram

Here a Package Diagram is used "freestyle" to show some of the other elements introduced by SysML, as well as some MD SysML features.

SysML Block Definition Diagram (BDD) in MD SysML

In MD SysML you are freely encouraged to use the UML InstanceSpecification to explore "instances", however they are not formally permitted in SysML diagrams (although they are used behind the scenes for carrying value state anyway).

The SysML Standard Port

The "standard" SysML Port is just the UML Port reappropriated for systems engineering, and may be used to carry Connectors and Interface contracts for software and electrical systems, as well as representing any point of isolation between a Block and its environment. A Port is a TypedElement.

FAQ: Why does the classifier-level Block stereotype show on parts in an IBD ?

When no "instance-level" stereotype has been applied to a Property the Stereotype of the Type (in this case «Block» applied to a Class) of the Property "shows through", as can be often seen on Property symbols in SysML Internal Block Diagrams (IBDs) and structure compartments. This is sometimes called a secondary Stereotype.

This is reminiscent of the translucency pattern of object-oriented programming, where a field or property of a class takes the static value defined on the owning class until it is explicitly set on an object.

Dr Darren has proposed that UMLTM notation could be improved by always showing such secondary stereotypes with a preceding colon, like «:Block».

Dr Darren's SysML Block reference "poster"

Grade If you spend a few hours studying and understanding just this one Block "poster" diagram by Dr Darren then you have used your time well.

Glasses Notice how a Property may be shown 3 different ways:

  1. As an attribute Property in the attributes compartment.
  2. As a Property end of an Association.
  3. As a Property symbol within a structure compartment (or within a dedicated IBD for the Block).