1. Universität Paderborn AG Softwaretechnik Towards Modular Modeling and Simulation of Production Control Systems Holger Giese und Ulrich A. Nickel AG Softwaretechnik, Universität Paderborn Warburger Str. 100, 33098 Paderborn {hg|duke}@upb.de

2. Universität Paderborn AG Softwaretechnik Holger Giese und Ulrich A. Nickel: Towards Modular Modeling and Simulation of Production Control Systems2/15 oProduction Control System oExecutable UML Class Model & Simulation oModularity & Separation for Executable Models oRequirements & Simulation oConclusion & Future Work Overview

3. Universität Paderborn AG Softwaretechnik Holger Giese und Ulrich A. Nickel: Towards Modular Modeling and Simulation of Production Control Systems3/15 Production Control System (PCS) oFlexible distributed control is complex to build oFrequent adaptation to new requirements or changes in the topology are required oProgramming languages (Ada, C, …) oTest & code corrections in the production environment oDesign and maintenance Methodology & UML oAvoid long downtimes oVerification is hard problem Simulation

4. Universität Paderborn AG Softwaretechnik Holger Giese und Ulrich A. Nickel: Towards Modular Modeling and Simulation of Production Control Systems4/15 Application Software Gate Bus Interface Sensors /Actors Processor NodesIDIdentification Unit Data LinksStStopper Travel DirectionM Motor Signal DirectionSSensor IDStM S S PCS: Overview & Elements

5. Universität Paderborn AG Softwaretechnik Holger Giese und Ulrich A. Nickel: Towards Modular Modeling and Simulation of Production Control Systems5/15 Executable UML Class Model UML Model describes: opossible system topology oReactive overall class behavior (Statecharts, SDL,..) Advantages: oOO concepts: e.g., class encapsulation oVisual modeling oHigh level view Signal Gate Track

6. Universität Paderborn AG Softwaretechnik Holger Giese und Ulrich A. Nickel: Towards Modular Modeling and Simulation of Production Control Systems6/15 Specification Topology Visuali- zation Simulation Control software Simulation kernel Java Virtual Machine Java Reflect Dobs Production- order Code synthesis Hardware configuration Executable UML Model Simulation

7. Universität Paderborn AG Softwaretechnik Holger Giese und Ulrich A. Nickel: Towards Modular Modeling and Simulation of Production Control Systems7/15 Classes & Simulation Simulation result: oCan detect coordination problems: deadlock, … oProvides insight into system dynamics (tinkering style) Limitations: oSystem has to be complete (closed) oObservations do only hold for very restricted form of subclass refinement

8. Universität Paderborn AG Softwaretechnik Holger Giese und Ulrich A. Nickel: Towards Modular Modeling and Simulation of Production Control Systems8/15 Modularity : Overall Synchronization Component Spec.: ooverall behavior oarbitrary structures Abstraction: ocombine processes obuild abstract process obehavior for layer C depends on (A || B) ono abstraction barrier for used layers Limitations: oState explosion problem (propability for error detection) oComponent exchange preserve results only when very restricted conformance realtion holds A B C Layer C

9. Universität Paderborn AG Softwaretechnik Holger Giese und Ulrich A. Nickel: Towards Modular Modeling and Simulation of Production Control Systems9/15 Modularity : Contract oReduce class behavior to external visible/relevant contract behavior oMultiple contracts (UML-RT ports)

10. Universität Paderborn AG Softwaretechnik Holger Giese und Ulrich A. Nickel: Towards Modular Modeling and Simulation of Production Control Systems10/15 Modularity : Partial Contract Border Component Spec.: oset of contract behavior olayered structures Abstraction: ospecification for layer C is C1 ||... || C4 opartial model simulation & analysis marbitrary usage of provided contracts mC5 || C6 || C7 assumed for used contracts Limitation: oembedding restricted to layered structures C1 C2 C3 C4 C7 C6 C5 Contracts are design elements, but the by abstraction steps derived abstract processes are not!! Layer C

11. Universität Paderborn AG Softwaretechnik Holger Giese und Ulrich A. Nickel: Towards Modular Modeling and Simulation of Production Control Systems11/15 Modularity: Open PCS Factory as open system with in and out contracts (ports): opossible Environments? oembedding?

12. Universität Paderborn AG Softwaretechnik Holger Giese und Ulrich A. Nickel: Towards Modular Modeling and Simulation of Production Control Systems12/15 Modularity : Implicit Component Behavior support even for oset of contract behavior and implicit dependencies oEmbedding only restricted by demand to ensure acyclic dependencies Abstraction: ospecification for C1, …, C4 Advantage: oMore flexible embedding when independent C1 C2 C3 C4 C7 C6 C5 Component C

13. Universität Paderborn AG Softwaretechnik Holger Giese und Ulrich A. Nickel: Towards Modular Modeling and Simulation of Production Control Systems13/15 Modularity : Implicit Component Behavior Open factory with implicit component behavior: oimplicit environment oembedding rule: depend has to remain acyclic

14. Universität Paderborn AG Softwaretechnik Holger Giese und Ulrich A. Nickel: Towards Modular Modeling and Simulation of Production Control Systems14/15 Requirements & Simulation Requirements are described Scenario-oriented: oexternal view osystem may realize suitable interleaving for multiple parallel requested tasks Factory Simulation: ouse for checking ouse for run-time assertions

15. Universität Paderborn AG Softwaretechnik Holger Giese und Ulrich A. Nickel: Towards Modular Modeling and Simulation of Production Control Systems15/15 Conclusion & Future Work Modeling PCS: ostrong requirements for control software omethodology & UML-RT ocode synthesis and simulation (partial) Validation via simulation: oearly failure detection ointeractive testing Modular simulation oimproved separation omodularity & scalability Future Work Realize extended concept Integrate time support