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, Paderborn

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

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

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

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

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

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

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

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)

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

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?

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

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

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

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