SDL Task Force

Draft Input for Kick-Off Review

Working Name

The result of the task force activities is a subset of SDL, with ‘enhancements considered to be essential in making the subset useful’. A working name should be chosen to simplify references to this work.  Suggestions to date include SDL--, Mini-SDL, Basic-SDL, SDL-Core, Simple-SDL; more suggestions welcome.

Working Slogan

“The documentation is the design, the design is the code, end of story!”.

Structure of Result

Following comments at the AGM, it is proposed to structure the result as a) Subset and b) Essential Enhancements. 

The main area of application driving the task force is defined to be telecoms, but members are welcome to suggest features needed for other domains, such as automotives & aerospace.  In practice this may turn out to be the design of state machines, so the main characteristics of state machines need to identified and presented.

Acceptable features that map conveniently between domains will be merged into the result; acceptable features that do not map well may be separated into groups. 

Scope

‘As a framework the task force will prioritise:

• the graphical representation, ensuring auto-layout is possible
• test capabilities, such as SDL based test scripts
• ASN.1 (1994) support, including encoding/decoding of PDUs
• associated methodology issues, such as maximum integration of tool chain.’

Based on this scope, the main areas have been identified as a starting point

1. Instantiation & Connectivity
   1. Dynamic or Static Instantiation
   2. Point-Point Connectivity
   3. Interfaces are Signal Lists, Lists of Signals
   4. Dimensioning
   5. Execution Model
2. Methodology
   1. Design
      View, edit, semantic check, validation
   2. Implementation
   3. Execution
      Trace, diagnostics, statistics, analysis of behaviour, link to source code.
   4. Documentation
      Readability, automated generation.
   5. Test All issues of design, implementation, execution & test are relevant for testing.
3. Applications Suitable for SDL Focus on features needed for these applications.
   1. Signalling Systems
   2. Control Systems
   3. Others?
   4. Applications Not Suitable?
      Dining Philosophers, financial mathematics, astronomical modelling, others?
4. Overlap with Other Languages
   1. ASN.1
      Encoding rules, language support for encoding/decoding, language support for accessing fields.
      Which part of ASN.1?
   2. C
      Statements, functions, input/output.
   3. Other Languages?
5. Graphical Representation
   1. Automatic Generation
   2. Flow Chart Symbols
   3. Resizing & Long names

Promotion

Activities for promotion of task force work to:

• SDL Users
• Industry Contacts
• Tool suppliers
• Standards Organisations
• Universities