“A picture is worth a thousand words.” Pictures, or model-based designs, as engineers refer to them, provide a natural means of communication. With the newest release of ANSYS SCADE System 15.2, systems engineers can use models and interface control documents (ICDs), rather than text files and long lists of data, to create and manage their systems designs.
However, when precision and complexity come forth, “data dictionaries” enter the game. A dictionary is a way to manage information in an exhaustive way but without the model, it’s not easy to get an overview of your system. The issue you’re then faced with is the consistency between the model and the dictionaries — if inconsistent, the situation is worse than without the model.
The model helps you to understand something that is not specified in the dictionaries. For example, the dictionary says that information “speed” goes from component A to component B, while the latest model shows no connection between these components, or no component is named A or B.
The SCADE System 15.2 release provides an efficient solution thanks to the model-based paradigm. Model-Based System Engineering (MBSE) solutions provides key features to manage complexity in systems engineering, in particular traceability with higher level textual requirements, automated checks of design rules, automated report generation, etc. SCADE System goes further with a feature dedicated to managing data dictionaries, while allowing for architecture drawing, and maintaining consistency between both.
Interface Control Documents Management
To look at how you can achieve this, let’s detail a workflow that SCADE System supports:
- Draw your system architecture with blocks, ports and connectors. Numerous features allow you to organize this with packages, multi-diagrams capability, graphical styles and alignments, etc.
- Directly import from Excel lists of data into blocks that are used to model components or functions. Data can carry as many attributes that the users customize, e.g. min and max values, safety level, timing information, etc.
- Propagate the data between the blocks through the connectors. Relying on a model makes very easy to choose at any place between broadcasting or multi-casting information. As the drawings rely on the model, this data propagation is immediately highlighted on the drawing: select any data in the model object browser, its path is highlighted on the opened diagrams.
- Verify with SCADE System checker that your model is correct with respect to your design guidelines. The checker automates the verification of design rules that you can customize yourselves, and generate a comprehensive report highlighting any violation of one rule. Some rules as provided as examples, for example to verify that all your data are produced once, and consumed at least once.
- Display ICDs in tables: this is the exhaustive, consistent, list of data at the interface of a block, at any level of the system, from each individual component to the top-level. The table provides not only the list of data each with its own properties, but also the block and port source and target that is directly accessed in the model. The information displayed in the table is customized with “queries” on the model. So you can easily add columns proving additional information from the source or target ports, or from properties customized on the connectors used for the data propagation.
- Export any of these tables to excel with a simple copy/paste, or from an export menu.
Because designing a complex system is never done in one shot, management of ICDs can be really cumbersome when not well supported by a tool. Thanks to the features listed above, managing changes in the set of data or in the architecture becomes simple and safe with Model Based ICDs that are always consistent.
To learn more about the newest release of ANSYS SCADE System, I invite you to download the technical paper that I presented at the ERTS conference entitled Data-Based System Engineering: ICDs management with SysML. And, if you have any questions, please do comment below and I’ll get back to you.