TRAIL: HOWTO simulate Dependency Injection of SysML Parametric calculations

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Quick start

The problem statement: A Client subscribes to an output value property but does not know what computes it or how

SysML keywords

SysML Parametric Diagram

constraint property

ConstraintBlock

constraint parameter

Keywords

Sometimes it is best to work on real-world problems; sometimes it is best to abstract away the essence of a subtle real-world problem and represent it in a purely mathematical fashion.

The problem addressed here arose from some work applying SysML to complex SysML Parametrics applications at Lendlease Digital; thanks to Graham Day for discussions.

It is assumed in this trail that the reader already knows the basics of SysML Parametrics, although you can probably learn it as you go.

And we need a definition of Dependency Injection:

Wikipedia: 'In software engineering, dependency injection is a technique in which an object receives other objects that it depends on. These other objects are called dependencies. In the typical "using" relationship the receiving object is called a client and the passed (that is, "injected") object is called a service. The code that passes the service to the client can be many kinds of things and is called the injector. Instead of the client specifying which service it will use, the injector tells the client what service to use. The "injection" refers to the passing of a dependency (a service) into the object (a client) that would use it.'

Typically, the injection - the choice of service implementation - is performed at run-time. For the case examined here, this means the choice of SysML Parametrics calculation (the constraint equation) will be chosen at run-time.

We'll see also how this approach is leveraged by so-called trade studies (a.k.a trade-off studies, and how the Magic Model Analyst^® (Cameo Simulation Toolkit^®) TradeStudy support makes it easy to inject combinations of instances from one or more instance tables.

Start here

The problem statement: A Client subscribes to an output value property but does not know what computes it or how

Sections

Slides in this trail

If you want to navigate the entire tutorial including the additional explanatory text, click on the title link of the first slide to view the full slide page, then use the next links to move through the slides pages. If you just want to view the slide images only in sequence, click on any slide to view it larger in a viewer, then click again to move through each slide in the tutorial trail.

The problem statement: A Client subscribes to an output value property but does not know what computes it or how

Variations on concrete implementations of I_A and the constraints with computations they carry

Parametric diagrams with BindingConnectors for concrete implementation blocks A1 and A2

Executable instance tables for A1 and A2 (concrete implementations of I_A)

Executable instance tables for Client with A1 and A2 instances (dependency injection)

Trade(-off) study for Client with A1 and A2 instances (dependency injection)

MultiClient with two injectable service targets

Trade study with multiple targets

A 2nd injection target I_B

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