SysML Reference Model Definition Model Based System Development in the Joint Strike Missile project Svein-Erik Søgård KDS/Missile Division

Agenda Introduction –Background –Goals for modeling –Challenges Model definition –Principles –Walktrough of process and reference model Summary –Lessons learned 27/10/2015Page 2WORLD CLASS - through people, technology and dedication.

Background Main motivation for MBSE in JSM –Lack of system and architecture level documentation in previous projects Many documents and model fragments but not up to date, poor value for money (waste), not systematically organized). Very hard for –Maintainability –Introducing new developers –Doing analysis (e.g. safety) –Initiative from Management (LEAN thinking) as well as a JSM core team of developers that would do it better 27/10/2015Page 3WORLD CLASS - through people, technology and dedication.

Background KDS Survey that concluded with SysML and MagicDraw™ modeling tool –Major player in MBSE –Simultaneously evaluated UML tool for SW modeling –smooth transition to SW development was important JSM project main focus so far on functional analysis & design, but also physical architecture is addressed MagicDraw™ is NOT «THE System Tool» –Used in conjunction with other tools –Information management Linking other documentation rather than duplicating it 27/10/2015Page 4WORLD CLASS - through people, technology and dedication.

Goals «Real» Model Based, –Not only drawings and model fragments –Consistent model with a set of well defined views System Model (SysML) characteristics –Complete functional description (concise, right abstraction level) focused on what the system shall do. Easy entry point to what the system shall do and how it works –Physical System Architecture that is precise and detailed about interfaces at different levels (How the system shall be constructed) –Specifications for component design (in other disciplines: SW, PLD electronics, mechanics) –Focus on maintainability (of the model and the product) 27/10/2015Page 5WORLD CLASS - through people, technology and dedication.

Challenges Project size (JSM) is too large to be optimal –“How to do” established later than desirable –doing development and establishing how to model in parallell –Too few resources to follow up new teams Culture (document centric, different philosophy & terminology) –Commitment to the process and methodology Commitment from engineers are even more important than commitment from management –developers tend to fall back to «their old methods» when they get pressed for time SysML is a complex language. Requires time to understand what to use and how to use it to make consistent models. 27/10/2015Page 6WORLD CLASS - through people, technology and dedication.

Reference Model Definition Motivation: SysML is a (too) complex language – we need to define which subset to use and how Steps: –Defined Modeling Process –Defined reference model Subset of SysML (elements and diagrams) Define metamodel of how model elements are related Model organization (views/perspectives) –Tools customization Profile (extension with DSL) Diagram Customization Validation rules 27/10/2015Page 7WORLD CLASS - through people, technology and dedication.

Reference Model Definition Basic Principles –Avoid redundancy and duplication of information –Be very clear about the different abstraction levels (hard!) –Shall not cover all details nor repeat or duplicate information from other tools (link in instead) 27/10/2015Page 8WORLD CLASS - through people, technology and dedication.

Reference Model Definition Process modeled using SysML Activity Diagrams Walkthrough (HTML generated from MagicDraw™) 27/10/2015Page 9WORLD CLASS - through people, technology and dedication.

Summary MUST make a standardization of modeling to make a maintainable model –Do systematic stakeholder analysis –Reference model, guidelines –Tools customization Customized to process and modeling style Suite of validation rules Build up a core team that is skilled before rolling it out –Use consultancy –Do peer modeling –Both SysML and tools experience required 27/10/2015Page 10WORLD CLASS - through people, technology and dedication.

Summary If possible – select a small project (but not too small) and cover all phases/aspects before rolling it out in large scale Do not try to cover all aspects of system engineering/modeling from the start (eat the elephant piece by piece) Be aware on separating between “throw-away” models and maintainable models –«less is more» 27/10/2015Page 11WORLD CLASS - through people, technology and dedication.

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