2 Systems Engineering Communications! Systems Engineering is an interdisciplinary approach and means to enable the realization of successful systems. It focuses on defining customer needs and required functionality early in the development cycle, documenting requirements, then proceeding with design synthesis and system validation while considering the complete problem.Time Delay!
4 Communications and Learning Verbal-LinguisticSharing words, writings, documentsWhy are we stuck here?Logical-MathematicalEquations, drawings, MatLab modelsEngineering disciplineVisual-SpatialPictures, charts, drawingsApproximately 30% of people!Other methods too…
5 What is SysML? SysML is a graphical language SysML is a method for communicationsSysML emphasizes the SE domainSysML is NOT a specific tool or methodologyMain Entry:lan·guage Pronunciation:\ˈlaŋ-gwij, -wij\Function:noun1 … (2): a systematic means of communicating ideas or feelings by the use of conventionalized signs, sounds, gestures, or marks having understood meanings (3): … (4): … (5): a formal system of signs and symbols (as FORTRAN or a calculus in logic) including rules for the formation and transformation of admissible expressions
6 SysML Relationship To UML For more info…SysMLUML 2.0Common Diagrams: Activity, Block Definition (UML2::Class), Internal Block (UML2::Composite Structure), Package, Sequence, State Machine, Use CaseNew Diagrams: Parametric Constraint, Requirement
7 SysML Trivia SysML is a UML profile Inherits the mature UML notationInherits UML “bloat”Compatible with UMLSysML is SE domain specific, UML is general purposeSysML abandons some of the software-centric aspects of UML
8 Our typical form of communications The dreaded “block diagram”
9 Simplified Block Diagram Track TargetReport PositionOrder of operation?SimulationFederationRelationship?RT ClockExecutiveInterface?What does a block diagram mean?????
14 Compare and ContrastBlock diagram with random or inconsistent meaning to symbolsComponent diagram with well-defined syntax and grammar
15 CommunicationsThe engineer must use a consistent, well-defined, and well-understood language to communicate the requirements and design to other engineers, otherwise the product will founder, fail, or be a disaster.For the systems engineer, that language is currently SysML.
16 Ένα πρόβλημα με καλη σαφήνεια είναι μισό λυμένω AxiomΈνα πρόβλημα με καλη σαφήνεια είναι μισό λυμένωTranslations courtesy Haratini E. Andre
17 “A problem well-defined is half solved.” Communicating WellIn order to communicate you must speak a common languageYou must share the problem definitionAcross culturesAcross spaceAcross TIME“A problem well-defined is half solved.”Lou Cohen
18 Matching the Language to the Problem Verbal-linguistic methods for system definitionWriting specs, ICDs, SRSs, etc.Logical-mathematical methods for system definitionModels, MatLab filesVisual-spatial methods for system definitionPicturesDrawingsCharts}Models too!SysML is a suitable language, iff you model your system. If you don’t, then it won’t work.
19 Όλα είναι ελληνικά σε μένα Is there a problem?You have to speak the modeling language, otherwise…Όλα είναι ελληνικά σε μένα(It’s all Greek to me)Translations courtesy Haratini E. Andre
20 INCOSE Orlando Presents: PrerequisitesYou must be able to use the languageYou must model your system as a standard practice“Speak” the languageLearn UML, SysMLPractice, practice, practiceYour boss must recognize the languageNever leave your boss in the darkNever make your boss look stupidYour boss must understand WHY you speak the languageYour customers (internal and external) must understand the language and the modelsINCOSE Orlando Presents:SysML Tutorial, June 8thBy Sandy FriedenthalLockheed Martin
21 The models they depict have enormous value to the SE process Why model?ModeldepictioninformationSystemdescribes1+1By themselves, drawings can have dubious valueDrawingDefineRequirementsDesign SystemImplementIntegrateThe models they depict have enormous value to the SE processRequirementsModel
22 Got Models? – Operational Concepts Do you do analyze operational concepts?Sample Use Case DiagramCopilot /GunnerTrack Target<<extends>>Scan by Pattern<<extends>><<extends>><<extends>>Autotrack ImageSelect Track ModeDrive Turret Manually
23 Got Models? - Requirements Do you model requirements and their relationships?Sample Requirements Diagram
24 Got Models? – Functional Decomposition Do you do functional decomposition? (DoDAF SV-4)Sample Activity Diagram
25 Got Models? – States & Modes Do you analyze states/modes? (DoDAF SV10b)Sample State DiagramPOWER APPLIED [ powerIsStable]SELF TEST FAILED / STORE FAILURE DATATEMP REACHES OPT / ASSERT READYENABLE CMD RCVDOPTIONS SET CMD( )[ options enabled ] / SET OPTIONOFF COMMAND RCVD / STORE DATATEMP FAULTEXECUTE COMMAND[ safety confirmed ]DISABLE CMD RCVDOff ModeWarmup ModeFailure ModeStandby ModeReady ModeFire ModeEXECUTION COMPLETEDentry: emit 3 pulsesentry: Assert Not Ready
27 Got Models? - Deployment Do you deploy components onto processors?Sample Deployment Diagram(borrowed from UML)
28 Got Models? - Parametrics Do you create parametric models?Sample Parametrics Diagrams
29 SysML Drawing Summary SYSML DIAGRAM PURPOSE UML ANALOG Activity diagramShow system behavior as control and data flows. Useful for functional analysis. Compare Extended Functional Flow Block diagrams (EFFBDs), already commonly used among systems engineers. Block Definition diagramShow system structure as components along with their properties, operations and relationships. Useful for system analysis and design.Class diagramInternal Block diagramShow the internal structures of components, including their parts and connectors. Useful for system analysis and design.Composite Structure diagramPackage diagramShow how a model is organized into packages, views and viewpoints. Useful for model management.Parametric diagramShow parametric constraints between structural elements. Useful for performance and quantitative analysis.N/ARequirement diagramShow system requirements and their relationships with other elements. Useful for requirements engineering.
30 SysML Drawing Summary - cont. Sequence diagramShow system behavior as interactions between system components. Useful for system analysis and design.State Machine diagramShow system behavior as sequences of states that a component or interaction experience in response to events. Useful for system design and simulation/code generation.Use Case diagramShow system functional requirements as transactions that are meaningful to system users. Useful for specifying functional requirements. (Note potential overlap with Requirement diagrams.)Allocation tables**dynamically derived tables, not really a diagram typeShow various kinds of allocations (e.g., requirement allocation, functional allocation, structural allocation). Useful for facilitating automated verification and validation (V&V) and gap analysis.N/AUML 2.0 Component, Communications, Object, Deployment, Interaction andTiming diagrams have not been included in SysML
31 Leaving SysML at Home Don’t bother with SysML if.. your process is centered on writing nothing but textual specificationsyou don’t model your systemsyour management won’t read SysML diagramsyour customer won’t read SysMLall you want to do is say you’re using it
32 Bringing SysML to Work Selling SysML to systems engineers Preaching to the Choir
33 Bringing SysML to S/W Engineers Selling pointsThey’re probably already using UML“now we can communicate better”
34 Bringing SysML to Management Selling PointsBetter communicationsReduced errors“Easy to learn”Break them in slowlyInterface to S/WImproved integrationSolid, proven technologyCustomers are asking for itCompetitors are using itDON’T ask for a $20K tool up frontUse SysML manually first, buy the tool laterSome managers just don’t get it
35 EE’s generally won’t care Bringing SysML to EEsChicken chicken chicken chicken chicken chicken chicken chicken chicken chicken chicken chicken chicken chicken chicken chicken chicken chicken chicken chicken chicken chicken chicken chicken chicken chicken chicken chicken chicken chicken chicken chickenEE’s generally won’t care(neither will ME’s)
36 Getting Started – One Idea Use the language any way you canVisio, PowerPoint, etc.Insinuate the language into existing work productsDrawings start appearing in specsControl the document = control the drawing inside itDo the analysis as part of the effort to write the CDRLMake the managers want itBuy the tool after SysML is part of your process
37 Why SysML? Standardized communications Improve life-cycle management - across space- across timeImprove life-cycle managementCapture the artifacts of systems engineeringEliminate dreaded Block Diagrams